6- *- x ARMY MEDICAL LIBRARY WASHINGTON Founded 1836 tWUE> «NJRTBJ Section... Number J&M^-C. Form 113c, W. D., S. G. O. e«-o 3—10543 (Revised Juno 13, 1936) DUE VWO WEEHWHUHI LAST DATE MAR 6 1963 JUL 7 1967 ^pj?,'„f7 ^|Iimi|Jului.v 'taiittoj^1 m MANUFACTURER gj£jjjjj|jj|l^^^^j^^ BENJ? PIKE J OPTICIAN. TIIEODOUTES| EVCLl.l'.O I 8c PASSES fl * Cha/iin OLD ESTABLISHMENT-—See new one built 1850, frontispiece to "Vol. I. 729237 PIKE'S ILLUSTRATED DESCRIPT.IYE CATALOGUE O F OPTICAL, MATHEMATICAL, AND PHILOSOPHICAL INSTRUMENTS, MANUFACTURED, IMPORTED, AND SOLD BY THE AUTHOR; WITH THE PRICES AFFIXED AT WHICH THEY ARE OFFERED IN 1856. % WITH UPWARDS OP 750 ESGRAVISSS, mostly original designs from the instruments of his establishment in the various departments of ELECTRICITY, MECHANICS, GALVANISM, OPTICS, MAGNETISM, ASTRONOMY, ELECTRO-MAGNETISM, SURVEYING, PNEUMATICS, NAVIGATION, HYDROSTATICS, METEOROLOGV, CHEMISTRY, &.C., &c. Designed to aid Professors of Colleges, Teachers, and others, in the Selection and Use of Illustrative Apparatus, in every Department of Science: BY BENJAMIN PIKE, JR„ OPTICIAN IN TWO VOLUMES. *£i "> \ T>Y C6 vol-i:- /i;1W SECOND EDITION, ENLARGED. "///j; rr|()JH NEW YORK: PUBLISHED AND SOLD BY THE AUTHOR, AT HIS OPTICAL, MATHEMATICAL, AND PHILOSOPHICAL INSTRUMENT MANUFACTORY, 294 BROADWAY, A FEW DOORS ABOVE THE PARK. q Pfe35. E,"^^accordi„g to Ac. of Co„gre»», i.. ll» year 1848, By BENJAMIN PIKE, Jr., I„ the Clerk's Office of the District Court for the Southern District of New York. 1 MAGNETIC INSTRUMENTS. -^ I I I f I ' l i I ■ ■ i]msA Bar Magnets. — (Fig. 409.)—These instruments are adapted for the experimental elucidation of that peculiar property conferred on bodies essentially composed of iron, whereby, under certain circumstances, they acquire the powers of polarity, attraction of unmagnetic iron, attraction and repulsion of magnetic iron, and the influence of inducing magnetism in other iron not previously magnetic. Price, 4 inch, 25cts.; 6 inch, 38cts. " 8 " $0.50 and $0.75. " 10 " $0.75 " $1.00. " 12 " $1.00 " $1.50. Artificial Magnets (Fig. 410) made of steel, are now generally used in preference to the natural magnet, or loadstone, not only as they may be procured with greater ease, but because they are far superior to the natural magnet in strength, and communi- cate the magnetic virtue more powerfully, and may be varied in their form more easily ; the most usual of which is the bar magnet, and the horse-shoe or U magnet; the latter is much the most powerful. The piece of iron used to connect the poles, or extremities of a horse-shoe magnet, is the armature or keeper, and by being kept on the poles of the magnet when not in use, preserves its power. Fig. 410. 6 benj. pike's, jr., descriptive catalogue. Many pleasing experiments with needles, keys, steel filings, and other iron or steel articles may be performed by the aid of the horse-shoe magnet. Price, 2 inch, $0.31 ; 3 inch, $0.50 ; 4£ inch, $0.75. " 6 " $1.00; 8 " $1.50; 10 " $2.25. Fig 411. Compound Horse-shoe Magnet.—(Fig. 411.)—Compound horse-shoe magnet, or battery of single horse-shoe magnets, held together by screws or other contri- vances. The association of several bars is a set. Mounting with an appropriate armature greatly increases the magnetic power, not only for suspending weights, but also the capability of making other magnets. Price, 6-inch, 3 6-inch, 8-inch, 10-inch, 12-inch, bars, $5.00. $7.50. $10.00. $12.50. Fig. 412. 12-inch, 5 bars, $16 and $20. Fig. 413. ^H o 02 Magnetic Needles.—(Figs. 412 and 413, as above.)—Mag- netic steel needles of various lengths and forms, mounted with central hard metal caps for suspending on pointed stands, for the purpose of illustrating the influence of ter- restrial magnetism as regards the horizontal directive force : also the polarity of a magnetic body, by its attractive and repulsive qualities, in relation to similar and dissimilar poles. Price, $0.38 to $1.00. MAGNETIC INSTRUMENTS. 7 Horizontal steel bar needles, prepared for delicate investi- gations. These needles are constructed of various shapes and dimensions, mounted with central agate, or ruby caps, and every precaution taken in selecting the finest quality of steel for their construction, and its treatment afterwards, in the formation of the needles, also in the method employed in the magnetization. Price, $2.50 to $5.50. Brass stand, with fine steel point, for the suspension of horizontal magnetic needles. Price, $1.00; wood stand with steel point, $0.25. Fig. 4U. Fig. 415. The Astatic Needle.—(Fig. 414.)—Two needles, perfectly similar in their form, and magnetic intensity, are turned with their poles in opposite directions, and placed upon the same axis perpendicular to their length. The adjustment of the opposing polarities of the two needles should be such, that the directive power of the combination resulting from the magnetism of the earth is very nearly balanced ; the compound needle being allowed to retain only sufficient power to bring it to a constant posi- tion when uninfluenced by any electrical current. This needle is very sensitive to even a feeble galvanic current, and is used in delicate galvanometers. Price, $2.00 to $5.00. Dipping Needle.—(Fig. 415, as above.)—This magnetic needle, the cap of which is mounted in small gimbals, or a universal joint, admits of the needle moving in a vcitical 8 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. plane as well as in a horizontal plane. This arrangement, with its stand and graduated arc, furnishes the lecturer with an instrument peculiarly adapted for the illustration of the real influence of terrestrial magnetism upon magnetic bodies, having free motion in all directions. Price, with graduated arc, $6.00. " without " $3.00. Fig. 416. Fig. 417. Small Dipping Needle tvith Graduated Arc.—(Fig. 416, as above.)—Small dipping needle, with brass graduated quadrant, upon which the needle shows the dip. If this small instrument be moved along a bar magnet, it illustrates the relative situations and tendencies common to a needle when acted upon by the influence of the earth's magnetism. For when placed on the middle or equatorial part, the mu- tual attractions of the north and south poles balance each other, and cause the needle to stand exactly parallel to the bar ; but as the needle is moved towards either extremity, it will be inclined according to its distance from the mag- netic poles. Price, $3.50 and $5.00. Dipping Needle with Graduated Ming.—(Fig. 417, as above.)—Dipping needle with graduated brass ring, upon which the needle indicates the inclination or dips due to ter- restrial influence. When the apparatus is passed over a bar magnet, a popular illustration is afforded of the action of the earth's magnetism. Price, $6.00. MAGNETIC INSTRUMENTS. 9 Magnetic Dirks, Arma- Fig. 418. tures, *> g. « stone-ware, glazed—plain, 4 ounce, j^ << " pint, $°' << " quart, $0. << " half gall., $1 tubu ated, 4 ounce, pint, $0 quart, $0 half gall., $1 Fig. 481. 50. 40. .50. .62. .75. .00. .50. .62. .75. .88. 25. Fig. 487. Iron Retort for Oxygen.—(Fig. 487, as above.)—This is an iron vessel shaped usually in the form of a bottle, hold- ing from one pint and upwards, and having an iron tube, bent or straight, screwed, or ground conically into the neck, and is used principally in producing oxygen gas. Price, $2.00 and £2.50. CHEMICAL APPARATUS. 63 Fig. 483. Fig. 489. Globe Receivers.—(Figs. 488 and 489, as above.)—Re- ceivers are vessels, usually of glass, of a spherical form, with a straight neck, into which the neck of the retort is usually inserted. When any proper substance is put into a retort, and heated, its volatile parts pass over into the re- ceiver, where they are condensed. They are made plain and tubulated, with ground stoppers. Price, - - gill, 25cts.; \ pint, 25cts. " - - pint, 37cts.; quart, 50cts. " stoppered, gill, 31cts.; i pint, 37cts. " " pint, 44cts.; quart, 63cts. Fig. 490. Fig. 401. The Alembic, for Sublimation and Distillation.—(Figs. 490 and 491, as above.)—The alembic is used for distilla- tion, when the products are too volatile to admit of the use of the retort. The alembic consists of a body, to which is adapted a head. The head is of a conical figure, and has its external circumference or base depressed lower than its neck, so that the vapors which rise, and are condensed against its sides, run down into the circular channel formed 64 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. by its depressed part, from whence they are conveyed by the nose or beak into the receiver. They are made of glass and stone ware glazed, usually of the capacity of one quart. Price, $2.50. Fig. 492. Beaker Glasses.—(Fig. 492, as above.)—These glasses are used for a variety of purposes in chemistry, viz. for mixing solutions and precipitating, also for boiling and even extract- ing any solution. They are generally made of very thin glass, and of the shape shown in the cut. They are particu- larly useful for boiling and concentrating solutions, and if made of good glass, will stand heat well. Care must be observed in selecting them, to see that the glass of which they are made contains no flaws, and also that it is equal in thickness, otherwise they are apt to crack. Four of them are sufficient for general use, commencing with one to hold two ounces, and increasing in size to half a pint. Price, 20cts. to 50cts. Precipitating Glasses.—(Fig. 493, as above.)—These are made of glass, and in various shapes ; those, however, shown in the figures are the best forms. They are used in pre- cipitating salts or other substances from the solutions in which they are formed. Price, 15cts. to 25cts. Funnels.—(Fig. 494, as above.)—These are best made of glass, and should be ribbed on the sides. They are used CHEMICAL APPARATUS. 65 for pouring liquids from one bottle to another, and also to support filter-papers when filtering any liquids. Price, gill, 15cts. : x pint, 18cts. " pint, 25cts.; quart, 38cts. Fig. 497. Fig. 498. Fig. 495. 80 70 -40 50 —10 Graduated Measure Glasses.—(Fig. 495, as above.)— These are made of strong glass, and are used for measuring liquids. They are of various sizes, but one of six ounces is the most useful. The quantity is marked by a graduated scale at the side, and usually commences with half a drachm, and so proceeds drachm by drachm to half an ounce, and up- wards to an ounce or more. r Price, 2 ounce, $0.62 ; 3 ounce, $0.75. « 4 " $1.00; 8 " $1.25. Graduated Glass Jar on foot—(Fig. 496, as above.)—This consists of a cylindrical glass jar with lip, on a foot, and graduated into 100 equal parts, or into cubic inches ; they are usually ten inches high and two inches wide. Price, $2.00 ; smaller, $1.50. Graduated Bell Glass.—(Fig. 497, as above.)—This con- sists of a tubulated bell glass, with cap and stop-cock, 6* 66 BENJ. PIKE'S, JR. DESCRIPTIVE CATALOGUE. graduated into 100 equal parts, and used in measuring vo- lumes of gas, transferring given quantities, ^ Price, with stop-cock, pint, b2.1o , qu< rt, » , «; ' .. « i gall. $3.50 ; gallon, *4.00. Fig. 493. Adapter.—(Fig. 498).—A glass ^.__________ .. tube open at both ends, used to U EflGT— * l^^iLJ-"" connect a retort with its receiver whenthe neck of the former is not long enough. Price, 25 cts. to 50 cts. Tubes of Glass, Porcelain, &c—(Fig. 499, as below.)— Tubes are made of glass, porcelain, stone-ware, brass, and lead and are used in distillation, evaporation, to connect apparatus for the conveyance of liquids and gases, and for other purposes, and may be obtained straight or bent in any form required ; they are usually furnished m lengths of about three feet long, varying in diameter from one eighth of an inch to one and a half. Porcelain and stone-ware tubes are usually about one inch in diameter, and two feet Fig. 499. lono-; small sized lead and brass tubes may be obtained in lengths of ten feet or more. Flexible tubes, the foundation being a spiral formed of twined iron wire, over which fine twine is braided, and then a coating of india rubber, and over that a braid of fancy colored twine, which is varnished and highly polished ; forming an elegant, useful, and very durable tube that may be bent in any manner, being quite flexible, and of important use in many pneumatic experi- ments, also used for conveying the gases in hydro-oxygen microscopes, compound blow pipes, dissolving view appa- ratus, &c. Price, small glass tubes in lengths of 3 ft., 15 cts. to 25 cts. " larger " " 31 cts. to 50 cts. or 63 cts. each. " fine porcelain tubes, 18 inches long, 63 cts. " " " stone-ware, " " 38 cts. to 63 cts. " " small lead, per foot, - - - - 8 cts. " " brass, " - - 121 cts. to 18 cts. " flexible tubes, half inch diameter, per foot, 86 cts. CHEMICAL APPARATUS. Dropping Tube, or Pipette.—(Fig. 500.)—The Fi<^m- dropping tube, or separating funnel, is a tube of glass, drawn to a point at one end, and furnished with a bulb in some part of its length, both ends beino- open. To use it, immerse the finer end in the liquid to be taken up, and thrust it down; the liquid will rise until it finds its level withinside ; then closing the upper end with the finger, it may be conveyed away. The partial or total removal of the finger occasions the fluid to drop from the lower end. Closing it again with the finger stops the flowing ; and thus, if there are two liquids in the tube, such as oil and water, the one may be separated from the other. Price, $0.38. Fig. 501. Tube of Safety.—(Fig. 501.)—A tube open at both ends, inserted into a receiver, the upper end communicating with the external air; the lower being immersed in water. Its intention is to prevent injury from too sudden condensation or rarefaction taking place during an operation. For if a vacuum be produced within the vessel, the external air will enter through the tube, and if the air be generated, the water will yield to the pressure from the confined gas or gases. It is now more fre- quently used of a curved form, like that repre- sented in the cut, with or without a bulb in the uprio-ht stem ; the lower end of this, instead of being immersed under the liquid in the receiver3 as the straight tube, is merely inserted into the tube. The requisite tightness and pressure is obtained by pouring a little mer cury, or in some cases oil, into the tube; this resting in the legs of the lower bend, keeps the vessel perfectly air-tight. Price, 75cts. Test Tubes and Stand— (Figs. 502 and 503, page 68.)— Test tubes are made of glass, and for convenience are used with a stand, but sometimes test glasses are used when the stand is not required. These tubes are for testing small quantities of the liquid or mixture under analysis. For in- 68 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. stance, if you suspect some substance to be present in the solution and wish to ascertain whether it is so or not, you pour a small quantity of the solution into a test tube or glass, and then add any other solution known to act on the sub- stance you suspect to be present. The solution you add is Fig. 502. known in chemistry as a re- agent. You must then judge by the result you observe in the solution, on the re-agent being added, whether the substance you suspect is present or not. Price, 3 in. 38cts. doz. " 4 in. 50cts. " 5 in. 63cts. " " 6 in. 75cts. " " 6 in mahogany frame, $1.00. Fig. 5! 3. Air Thermometer.—(Figs. 504 and 505, next page.)—This instrument consists of a glass vessel or bottle, with a broad base and narrow neck, containing a colored liquid, a ; along tube having a glass bulb blown at one end, b, the other ex- tremity of the tube being open, and plunged in the colored liquid ; and a scale of equal parts, c. Heat is applied to the bulb to expel a part of the air, which permits a portion of the colored fluid to rise in the tube ; this fluid column indi- cates the slightest changes of temperature by risino- when it is diminished, and falling when it is increased ; became every increase of temperature expands the air in the bulb occa- sioning it to press upon the fluid column and force it'down while any decrease of temperature contracts the bulk of the CHEMICAL APPARATUS. 69 air, and permits the fluid to rise. This instrument is not capable of measuring variations of temperature through any very considerable range, and it is liable to other objections; yet, notwithstanding, it is still applicable, from its great de- licacy, to many purposes. Fig. 504. Fig. 505. Price, with dividing scale (Fig. 505) $1.00. s-^ ^-^ " without, " " « $0.50. (3 C )b " tube only (Fig. 504) - $0.19. Fig. 506. Boyle's Thermometer.—(Fig. 506, as above.)—One of the earlier, and consequently more imperfect thermometers. It is, however, superior to any previously in use. It is simply a glass tube, open at both ends ; one end cemented into a bottle half full of some liquid ; the cement preventing any escape of the air which is above the liquid. Any increase of temperature rarifies the air, and drives the liquid further up the tube ; on the contrary, a decrease of temperature occasions it to subside. There was no scale attached to this thermometer. Evaporating Dishes.—(Fig. 507, as above.)—These are best made of Wedgewood's ware, and are employed in the evaporation of solutions, so as to enable the dissolved body to assume the crystalline form. These dishes are made in such a manner, that a large surface of the liquid to be evapo- rated, may be exposed to the air at one time. They usually have a lip for the convenient pouring off of any remaining liquid, after the crystals are formed on the bottom of the dish. They are made of a variety of sizes, usually from two to seven inches in diameter. Price, 25cts. to 63cts. 70 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Fig. 508. Blow-Pipe.—(Fig. 508, as above.)—This is an instrument by which a small jet of air is directed laterally into the flame of a lamp or candle, so as to divert it in a long slender cone upon a piece of charcoal or other substance so placed as to receive it. When a flame is thus urged by the blow- pipe, the extreme heat is just at the tip of the outer white flame, where the combustion is most perfect, and where substances are rapidly burned or oxidized ; whilst the inte- rior blue flame, in consequence of its excess of combustible matter, abstracts oxygen from, or reduces substances. So that several metals, when thus heated before the blow-pipe, are alternately oxidized or de-oxidized by being placed in the outer and inner flame. The blow-pipe is of important service to the chemist, in enabling him to ascertain easily and quickly, the effects of intense heat upon a variety of substances ; and he frequently has recourse to it in order to distinguish metallic and earthy minerals from each other, and to ascertain in a general way, the nature of their com- ponent parts. Price, 38cts. and 50cts. Blow pipes, with reservoirs for condensing the moisture of the breath. Price, 63cts. and $1.50. 509. Crucibles.—(Fig. 509.)—The cru- Ocible is a vessel usually made of well hardened earthen or stone ware, in constant use in the chemical labora- tory for performing fusions of metals and other substances. Price, 6 cts. to 38 cts. per nest. CHEMICAL APPARATUS. 71 (Fig. 510.)—Small crucibles of Wedge- Fig. 510. wood's ware, with or without covers. Price, 25 cts. to 50 cts. 9 Spirit Lamp.—(Fig. 511.)—A small Tamp which is fed by spirits of wine, rather than by oil, producing a large and hot flame, though little light and no smoke ; the lamp being used in chemical operations, to heat retorts, test tubes, &c, and not for the light it affords. Spirit lamps are usually made of glass, with a brass top to hold the wick, and supplied with a cover, which fits over the top when it is desirous to extinguish the flame. Price, - - - $0.75. extra large, $1.00 and $1.25. Mortar and Pestles—(Fig.512.)—are so well known in every day use, that a de- scription is scarcely necessary. The che- mist requires for general use, one of glass, Wedgewood's ware, or marble, with pestle of the same description. They are used to pulverize and mix minerals, earths, and other substances; as it is necessary in analysing to reduce nearly all the sub- stances to powder before you commence the analysis. Price, 50 cts. to $ 1.50. Spatulas.—(Fig. 513.)—These Fur- 513. are made of steel, and are used ( arr ; to mix powders, to scrape out the contents of mortars and capsules, &c. Price, 38 cts. Retort Stands (Figs. 514 and 515, next page), with flat, oval, or rectangular foot, rod twenty inches long, having three rings two and a half, three and a quarter, and four inches in diameter, with brass sockets and thumb screw. Price, $1.50. 72 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Fig. 514. Fig. 515. CZ>4a Retort stands with rectangular iron base, ten inches long, hav- ino- two rods and six rings of the size of the former. ^ Price, $3,00. Fig. 516. Cooper's Lamp Furnace.—(Fig. 516, as above.)—A lamp which is made of an elongated form, and is furnished with two rows of broad wicks, the whole or part of which may be lighted at once. Professor Faraday recommends this simple furnace as valuable for the heating of tubes, or any long and narrow vessel. Near the ends are two twisted wires, for the support of the tube to be heated. Price, $2.00. Knight's Assay Lamp.—(Fig. 517, next page.)—Such is the name given by Mr. Knight, Foster Lane, to an extremely useful Argand lamp, adapted to heat retorts, and for general chemical purposes, a is a flat, short, cylindrical vessel, for containing the oil. b is a double cylinder of tin, about an inch in diameter. The outer cylinder passes through, and is soldered air-tight to the oil vessel; the inner cylinder passes from the holes below to the centre of the "flame. The oil and the cotton pass between the two cylinders, b is furnished with a screw below, which screws on to the foot c. d is a rack and pinion to regulate the height of the wick. e, e, e, are three wires, formed into a frame-work to support anything which is to be heated; these wires slide up and down in sockets on the sides of a and c. f is a hole for the supply of oil. There is usually a copper tube placed 4199999999 CHEMICAL APPARATUS. 73 over the flame, in the manner of a lamp-glass, to concentrate the heat by preventing its radiation sideways. Price, $5.00. Knight's Chemical Furnace.—(Fig. 518, as above.)—This is one of simple construction and of general application. It is represented as follows :—a, is the ash-hole door; b, the fire-place door, in which muffles, crucibles, &c, are to be introduced ; c, a door above the fire for introducing retorts. The top also may be wholly removed to insert a still or sand bath, d, e, are doors of different heights, leading to the fire, for the more convenient introduction of different appa- ratus ; f, the hole for the introduction of a gun barrel: g and H, handles by which the whole furnace may be re- moved. Price, $8.00 to $12.00. Stone Ware Portable Table Furnace.—(Fig. 519, as above.) —This furnace of stone ware, and capable of standing an intense heat, consists of three parts that fit upon each other, each part being firmly bound with iron hoops. A fire made in the bottom part—the two upper pieces being removed—will serve for heating materials in crucibles, ladles, retorts, &c. If the middle portion of the furnace is placed above the bottom part, a larger fire may be made, and if an iron or copper dish be fitted into the upper rim, it may be used for heating sand ; and thus a small sand bath will be obtained, in which retorts, flasks, evaporating dishes, &c, 74 BENJ. PIKE'S, JR., DESCRIPTIVE CATA may be placed, for the purpose of carrying on a variety of operations. When the roof, or uppermost part is placed above the middle portion, and the openings in the sides of the furnace closed, a very intense heat may be obtained, which will be applicable to several purposes such as the meltino- of metals, and the reduction of metals from their ores. °The heat may be further increased, by affixing a long funnel of sheet iron to the chimney, so as to increase the draught of air through the fire. Two holes are made on opposite sides of the furnace, to enable an iron or porcelain tube to be passed through the body of the fire ; as in the production of hydrogen, these holes have stoppers fitting for effectually closing them when desired. Three sizes, seven, ten, and twelve inches in diameter. Price, $3.75 ; -*5.50 ; and $7.00. Fig. 520 Dr. Black's Furnace — (Fig. 520.)—A very service- able portable furnace; used for chemical operations, and which may be applied to numerous other purposes. a is a vessel of sheet iron, lined around the part where the fire is with fire brick, that the heat may be the better retained. b is chimney, which may __lengthened at pleasure .— is an aperture at the the be c top, for the reception of an iron sand or water bath, d, d, are two sockets for iron rods, which have a cross bar at top, to suspend various boilers by, that they may be over the fire, e is a porcelain tube or gun barrel, passing through the fire, for the production of certain gases. This may be removed when not wanted ; when one hole being stopped up, the other will hold the nozzle of a pair of bellows, f is an aperture, with a sliding door for the reception of a muffle; g is a door, by which a crucible may be put in the fire ; and n is the ash-pit. The fuel may be kept in the cavity under the chimney. Price, $15.00. CHEMICAL APPARATUS. 75 Tongs.—(Fig. 521, as below.)—Chemical tongs are made of iron. One pair straight, and another crooked should be obtained, and of the shape shown in the plate. Their use is so well known that further description is unnecessary. Price, $1.00. Fig. 521. Fig. 522. J U ^^ fixed a shelf, and also a sliding shelf supported by two wires, having a funnel on the under side ; the sliding shelf may be set at any distance across the vessel; there is also a small spout at the side to prevent the water overflowing. The use of the pneumatic trough is in collecting gases. Supposing gas is issuing out of the beak of a retort, and that beak were placed beneath the funnel, the shelf being covered with water, it is evident that the gas would pass through the funnelled hole, and ascend into the air if the hole were uncovered, or else into a gas jar or other vessel placed over the hole. Also in passing through the water, the gas becomes purified and cooled. Price, - $2.00. larger, $2.50. Cooper's Mercurial Tube.—(Fig. 523, next page.)—This small instrument supplies the place of a mercurial trough. It consists of a bent tube, closed at top, open at the foot, supported in any manner which may be convenient, and filled previous to use with mercury. The open end is then connected with a retort, or alembic, which is giving off the 1963 Stop-Cock.—(Fig. 524, as above.)—The ordinary name given to the small brass taps or cocks used in pneumatic apparatus, and of which the figures are representations. The first figure shows the common stop-cock, which has a male screw at each end. The figure on the side of it is a connecting piece, used to join one stop-cock to another, when it is necessary to transfer gases through or into them. The lower figure shows a stop-cock so contrived at one end, that a bladder may be firmly united to it; the other end having a small screw, to which a tube or other apparatus may be attached. Price, .... $0.75. " large, for air pump apparatus, $1.00. " connectors, - $0.25 to $0.50. Binding Screw.—A term applied by opticians to denote the screws by which the wires of galvanic batteries, electro-magnetic apparatus, and other similar things are bound togetlier, during the time of their action. As good metallic contact is neces- sary in electro-magnetic experiments, the extreme point of the upper screw, as well as the end of the wire to be inserted, should be made bright, when wanted for use in delicate experiments. Price, 2Sets. Bell- Glass and Bladder Apparatus.—(Fig. 525, next pao-e.) —One of the most extensively useful and convenient articles of chemical apparatus is what is termed the bell-glass and CHEMICAL APPARATUS. 77 bladder apparatus. It consists of a bell-glass, furnished with a brass cap and stop-cock, and a small connecting piece with two female screws, by means of which a second stop- cock, affixed to a bladder, or to any other vessel, may be connected with the stop-cock and the receiver. If the bladder has been previously compressed, and a communica- tion be then made with the bell-glass by opening both stop- cocks, the gas contained in the bell-glass may of course be transferred into the bladder; by pressing down the bell- glass into the water of the pneumatic trough, the gas will be forced up into the bladder; the stop-cocks being then shut, the bladder must be removed. Fig. 526. The above cut (Fig. 526) re- presents a brass tobacco-pipe, furnished with a stop-cock, that it may be connected with a blad- der for throwing up soap-bub- bles, filled with hydrogen gas, or with a mixture of hydrogen and oxygen gas, for explosion. Blow some soap bubbles, filling them from the bladder of hydrogen, furnished with a brass pipe ; they will ascend rapidly to the ceil- ing ; if they are intercepted in their course by a lighted candle, , they will explode with a dull report, and a flash of yellow light. A jet is also con- nected with the apparatus, by which a small stream of hydrogen gas may be burned, and by holding a glass tube about two feet long over the flame, musical sounds will be produced by the vibration of the tube, which may be varied as the tube is raised or depressed. Price, with jet, pipe, and gas bag, quart, $3.75. « " " " " half gall., $4.00. " " " " " gallon, $4.25. 7* Fig. 525. 78 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Fig. 527. Flexible Gas Bags.—(Fig. 5*27.) __Gas bags made of India rubber cloth are very convenient for hold- ing gases ; they are made of vari- ous sizes, from one foot to two feet in diameter. One is repre- sented in the cut, having a large stop-cock and mouth-piece, as used for inhaling nitrous oxide gas. Price, 12-inch, - - - $1.50. " 15-inch, - - - $2.00. " 18-inch, - - - $2.50. " 24-inch, - - $3.50. " with large stop-cock and mouth-piece, - $4.00. " large gas bags for com- pound blow-pipes, oxygen microscopes, liquid will appear to boil "€s rather than rise in pulsations. Fig. 549. Chryopherus.—(Fig. 549.)—An instrument for illustrating the effect of evaporation in producing cold. It consists of a glass tube, from 18 inches to 2 feet in length, having an in- ternal diameter of one-fourth of an inch. The tube is bent at right angles near the ends, both of which are terminated by bulbs, as in the above figure ; or bent at one end only, as represented in Fig. 549, next page, which is the strongest and preferable form. In constructing this instrument, one of the bulbs is nearly filled with water, which being made to boil, the air is expelled from the tube and bulbs, which re- Fig. 548. Price, 50 cts. 92 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Fig. 549. main filled with steam. The open bulb is then closed, bv melting the glass at its capillary termination. When the empty bulb is im- mersed in a mixture of salt and snow, the vapor existing within it is condensed, which removing pressure from the surface of the water in the other bulb, enables it to evaporate rapidly; and the vapor being condensed as speedily as it is formed, the water is readily frozen. Price, $1.75. Fig. 550. jlfy Apparatus for showing Sjuciflc Heat—(Fio-. 550.)—In this arrangement there is a wooden base supporting five glass tumblers, over which there is a metallic frame, having a hook over each tumbler, to each of which there is suspended near the bottom by a cord, a metallic ball; two of the balls are of iron, one of copper. one of tin, and one of lead, each weighing exactly half a pound. To use, they are to be suspended by their cords in boiling water, and each will be heated to 212 degrees ; they are then quickly suspended in the separate tumblers, each containing exactly the same quantity of cold water, and all of the same temperature. As the quantity of water and the temperature in each vessel is the same, and the five balls of equal weight, we should suppose that the water would be equally heated, but we shall find that the lead will raise the temperature the least, the tin more, the cop- per more yet, and the iron most of all, each imparting a different quantity of heat, except the two iron balls, which will be alike. The heat imparted by each ball to the water in which it is immersed is called its specific heat. Price, S4.00. CHEMICAL APPARATUS. 93 Different Fluids Expand Un- Fi«-551 equally.—(Fig. 551.)—The ap- paratus for illustrating this ex- periment consists of three glass tubes with bulbs on their ends of exactly the same size, and filled with different liquids to the same height, a may be filled with alcohol, b with water, and c with sulphuric acid, to each is fixed a scale ; they are suspended in a tin O trough, and when hot water is poured in, the fluids will be found to rise to different heights, according to their expansi- bility ; the alcohol will be the highest, the water next. Price, with 16-inch tubes, $4.00. The Conductometer.—(Fig. 552.)— The conductometer is an instrument for illustrating the relative conducting power of different metals, and consists of a circular plate of brass, with a hole in the centre, the edge perforated with holes into which are inserted rods of different metals, of the same size and length, each having a small cavity in its extremity for holding a piece of phosphorus; on holding the plate over the flame of a spirit lamp, the heat will be conducted along the different metallic rods, inflaming the phosphorus first in that which is the best conductor, and in the others according to their conductibility. The arrangement usually is copper, brass, iron, tin, zinc, lead, and glass. Price, $1.75. Expansion of Metal by Heat.—(Fig. 553, next page.)— This instrument consists of a cylindrical piece of iron, hav- ing a handle adapted to it, and fitted to a piece of metal having the ends bent up, so that it may just pass through lengthwise, and at its ends go through a round hole ; when heated in the fire, it will be too long to pass in one direction, and too thick to pass in the other. Having become cold, it will again fit and pass through as before. The metallic plate is supported on a mahogany base. Price, $1.50. 94 benj. pike's, jr., descriptive catalog Fig. 553. The Ring and Ball to short) Expansion by Heat.—(Fig. 554, as below.)—This is a very elegant way of showing the same experiment as the last. It consists of a brass ball, suspend- ed from a brass pillar bent over at the top; on the pillar slides an arm bearing a brass ring, exactly fitting the ball, and which when cold will readily pass through ; on heating the ball, by a small spirit lamp, it will be too large to pass throuo-h ; when cooled it will pass as before. The whole is mounted on a neat mahogany base. Price,$2.25. Fig. 551. Fig. 555. Pyrometer.—(Fig. 555, as above.)—This arrangement consists of a base of mahogany about twelve inches long, to which are attached two upright pieces which areimmovably held in their position by metallic braces, extending from the one to the other; between these there is a rod of metal, supported at one end from the point of a screw, and at the other from the shorter end of a bent lever, the axis of which is fastened to the wood. The longer end of the level CHEMICAL APPARATUS. 95 Fig. 557. is connected with a cord, which passes round a wheel on the centre of an index, to another lever on the opposite side, intended to balance the first lever. Over these levers are springs, to keep the cord tight. The index and wheel on which the cord moves is fixed to an upright support, having a graduated brass ring, divided, and numbered on its face from 0 to 360. A rod of any metal, the expansion of which is to be tried, is put between the point of the screw and the lever, as before described, and as soon as the heat of the spirit lamps beneath is applied the metal will begin to expand, and its com- parative degree of expansibility will be shown by the distance to which the index moves, as noted on the graduated circle. In comparing different metals with this, it will be necessary to make the rods of the same size, and apply the heat of the lamps the same length of time. Price, $3.50. Fire Syringe.—(Fig. 556.)—This instrument is used for procuring an instantaneous light, by means of the condensation of air. It consists of a stout condensing syringe, having a solid piston with a hole, for containing a small piece of tinder, at the end. Upon forcing down the piston quickly, the air within the tube is rapidly condensed, and the conden- Fig. 556. sation occasions so great an evolution of heat as to light the tinder. Price, $1.00. A larger and more elegant article (Fig. 557) with glass cylinder for showing the flash of light accompany- ing the ignition. Price, $6.00. Caloric conducted slowly by Fluids downwards.—(Fig. 558, next page.)— This apparatus, to show that caloric is conducted by fluids slowly in a downward direction, consists of a fun- nel-shaped glass vessel, having an air thermometer, with a ball of consider- 9G BENJ. PIKE S, JR. DESCRIPTIVE CATALOGUE. Fig. 558. Fig. 559. able size, and fixed in the lower part of the funnel, the tube projecting through and containing a few drops of colored alcohol, and dipping into a cup containing the same liquid. To use, pour water into the funnel till it covers the bulb of the thermometer to the depth of half an inch, and upon the surface pour a small quantity of ether and set fire to it. Much heat is given out in the combustion of the ether, yet the water will not transmit it downwards in a sufficient quantity to affect the thermometer. The experiment may be varied by suspending above the flame of the ether, a glass or metal- lic vessel, containing the same quantity of water as the funnel, which will be found, after the ether is burnt, to have received a much greater quantity of heat than the lower one, as the thermometer will indicate. Price, - - $0.75. " with stand, $1.75. Steam Boiler.—(Fig. 559.)—This neat appara- tus, called the high pres- sure boiler, shows in a very lucid manner, the properties of steam, when under more than ordina- ry pressure. It consists of a strong brass globe or boiler, having a long and strong glass tube open at both ends, pass- ing through a stuffing box, air-tight in the top CHEMICAL APPARATUS. 97 of the boiler ; and extending to the bottom on one side there is a thermometer also passing through a stuffing box, air- tight, the ball within the boiler, and the scale on the outside, whicli has a stout glass shade to protect it from being broken; on the other side of the boiler there is a stop-cock with a pipe that may be disconnected ; the boiler is sup- ported on a brass stand, and the heat is applied by means of a large spirit lamp beneath. To use, a small quantity of mercury, about half a pound, is poured in, and the boiler about half filled with water, leaving the stop-cock open ; heat the globe with the lamp till the steam issues from the pipe, when the thermometer will stand at 212°, but will immedi- ately begin to rise, forcing the mercury up into the glass tube, and when it has reached the height of thirty inches, or the pressure of an additional atmosphere, the water will be heated to a temperature of 250°. Pour half a pound of water into the boiler, and apply the heat till all is converted into steam, having the pipe immersed in a vessel containing five pounds of water, at 60°, it will raise the temperature of the five pounds to 160°, or will boil a smaller quantity. Price, $15.00. Wollaston'i Steam Apparatus.—(Fig. 560.)— Fi«- 56°- Is a small but neat contrivance of Dr. Wollas- ton, to illustrate the principle of the condensing steam engine. It is represented annexed, and consists of a glass flask fitted with a belt out- side, and handle screwed to the belt. Inside it has a solid piston, working with little friction, yet steam-tight, up and down. A little water or ether is placed in the bulb of the flask and made to boil; the piston is then put in, and the bulb being dipped for a moment in cold water, the steam withinside condenses, and the piston descends ; making the liquid boil a second time drives up the piston, &c. ; thus the piston rises at every formation, and falls at every condensation of the steam. Price, $1.50. Calorimeter.—(Fig. 561, next page,)—An instrument for measuring the quantity of heat contained in any body, the temperature of which is above thirty-two degrees. It con- VOL. II.—9 98 ;'s, JR., descriptive catalogu Fig. 561. sists of two metallic vessels, placed one within the other, with a space between them; each vessel being furnished with a stop-cock at bottom. The vessels have each a closely fitting cover, which covers have also a space between them. If the space between the vessels be filled with melt- ing ice or snow, this will gradu- ally melt away, and the water formed run out by the cock, a ; by this arrangement the tem- _ perature of the inner vessel will always be that of the freezing point, or the thawing point, which is the same thing. A third vessel, b, is now placed within the second, and the space between the two inner ves- sels also filled with melting ice. It is evident that the ice contained in the second vessel, cannot be affected by the external air ; therefore, when a heated substance is placed within b, it will melt a certain proportion of the inner stratum of ice, the quantity of which melted, and conse- quently the quantity of heat parted with, to lower it to 32°, is ascertained by the quantity of water which flows out of c. Price,$8.00. Fig. 562. Reflectors, <&c, for Radiation of Heat.—(Fig. 562.)— Reflectors arranged for the radiation of heat, commonly called Pictet's Apparatus, consist of two concave reflectors, or mirrors of brass, or planished tin, twelve inches or more in diameter, and mounted on mahogany stands, having rods, chemical apparatus. 99 on which they slide up and down; there is an iron ball, about three inches in diameter, having a ring in it for more convenient handling, and having a stand supporting it opposite the centre of the mirrors, and also a differentia*1 thermometer, supported by a mahogany stand. To use, place the mirrors at the same height, on a table, exactly facing each other, and from ten to fifteen feet apart And in the focus of one of the mirrors (usually four and a half to five inches) place the iron ball, heated a little below redness, and in the focus of the other mirror, place tht thermometer, which will indicate a considerable elevation of temperature. Place a piece of phosphorus in the focus of the mirror, and it will be ignited. The rays of heat from the iron fall on the nearest mirroi and are reflected in a direction parallel to the axis of the mirrors; they then meet the second mirror, and are con- centrated on the thermometer, or phosphorus, in the focus of the mirror. Care must be taken to have the mirrors arranged in a common axis. Price, of 12-inch planished tin, with iron ball stands and differential thermometer, $ 8 00. " of 12-inch brass, - - - $20.00. " of 18-inch, " - $32.00. Leslie's experiment of a vessel on a stand having different radiating surfaces. Price, $1.50. The Still.—(Fig. F*s- 563 563.)—An appara- tus for the distilla- tion of liquids. It includes the body, or boiler, to which is attached the head, forming the com- munication between the boiler and con- denser, or worm- pipe, from the ex- tremity of which the distilled liquid passes in successive drops, or a small continuous stream. As these stills are made to act by means of a lamp, the whole process of dis- tillation may be performed on the table, without dirt, offen- 100 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. sive smell, or other inconveniences. Aromatic waters and essential oils may thus be obtained from lavender, roses, and other plants and flowers; and alcohol and brandy may be distilled from wines, cider, &c. They are usually made of copper, the boiler holding from one quart to a gallon. PF Price, $6.00 to $8.00. Fig. 564. cal Hope's Eudiometer (Fig. 564) consists of a glass bottle, holding about a gill, hav- ing a stopper in its side; and a glass tube closed at one end, and ground into the neck of the bottle at the other end. The tube is graduated into 100 parts. It is used in the examination of gases, atmospheric air, &c. Its mode of use is, to fill the gradu- ated tube with the gas to be tried, and fill- ing the bottle with some solution, capable of absorbing the gas, or one of the gases, if a mixed gas, as the atmospheric. The oxygen may be absorbed and its amount indicated by opening the stopper in the side under water, when the liquid will rise in the tube. Price, $2.50. Fig. 565. lire's Eudiometer (Fig. 565) consists of a glass tube bent in a tj form and closed at one end, the closed tube being gradu- ated into 100 equal parts, and having in- serted near the end, two platina wires, the outer extremities being formed into rings, or small balls for the passage of an electric spark. In the analysis of atmospheric air, a known quantity is introduced, and to it added a like quantity of hydrogen gas ; the remainder of the graduated tube, bend, and a portion of the open tube being occupied with water. The thumb is placed on the open end of the tube, and the gases exploded by the passage of an electric spark between the platina wires. The quantity of gas left is then ascertained, and deducted from the original quantity, one-third of the remainder being the quantity of oxygen contained in the atmospheric air examined. Price, $4.00. CHEMICAL APPARATUS. 101 Pepy's Gas Transferrer.—(Fig. 566.)—A *>g-5G6. small instrument for the conveyance of a small quantity of gas from one vessel to ano- ther. It consists of a glass tube, shaped as in the cut, both ends being open, and one of them drawn to a fine point. A tight piston and rod fits into the straight part of the tube. All the parts of the instrument below the pis- ton are filled with mercury. To use the in- strument, immerse it in a jar of gas, by passing the point upwards through the mercury in the mercurial trough. Draw up the piston, which will draw up the mercury also, and suffer the gas to enter the point of the transferrer. When enough gas has entered, depress the point below the surface of the mercury, and elevate the piston a very little to draw a globule of mercury into the fine orifice. When this has been done, the instrument may be taken out, and the gas it contains be carried where it may be required. Price, 75 cts. Glass Syringe.—{Fig. Fig. 567. 567.)—This instrument is formed of a piece of straight glass tube drawn at one end to a point, having a piston packed with tow attached to a wire handle. By means of this instrument a globule, or small quantity, may be drawn into the tube, and transferred to any other vessel. Price, 75 cts. Kig 56a Apparatus to show the Condensation of Liquids by Mixture.—(Fig. 568.)—This consists of a tube of glass having a double globe, as represented in the cut. To use it, fill the tube and one ball with one liquid, as water, and the other ball with another, as alcohol, sulphuric acid, &c. ; cork it and turn it upside down. The diminution of volume when the two are mixed together will be seen in the tube. Price, $1.25 to $3.00. 9* 102 BENJ. PIKE S, JR. Fig. 569. DESCRIPTIVE CATALOGUE. The Tube and Flask Holder. —(Fig. 569.)—This consists of a metal rod supported on a ma- hogany or metal stand ; on the rod is a movable ring, having a milled-head screw by which it may be fastened at any height; on "the side of the ring opposite to the screw is a pair of spring forceps, so formed as to receive the necks of various sized flasks, tubes, &c, and by the draw- ing of a slide on the forceps the flask or tube may be conve- niently held. The cut represents a flask thus supported, having a bent tube connected to the neck of the flask by a cork through which the tube passes, the other end of the tube being immersed in a jar of water; a spirit lamp is placed under the flask. Price, $1.50. Fig. 570. Apparatus for Distil- lation and Condensation of Liquids.—(Fig. 570.) —This arrangement con- sists of a glass retort supported on a common retort stand by one of the rings ; a spirit lamp beneatli: a retort stand supporting a tubulated quilled receiver, the neck of the retort entering the tubular neck of the re- ceiver, the quilled neck of the receiver being inserted into a flask surrounded by a jar of cold water; another retort stand supporting a funnel of water, which by drops falls on folds of paper on the neck of the retort, and from thence dropping into a bowl beneath. In the distillation of some ether the annexed cut will assist the understanding of several means of condensation. The ether passing from the retort meets first with water trickling from a funnel and falling upon folds of bibulous paper placed over the stem of the retort. A little further down the neck, water drops from a vessel at a on the neck, and from that to a vessel beneath ; then passing into a tubulated receiver, it is partly cS CHEMICAL APPARATUS. 103 cooled by the air striking the sides of the receiver. Finally, the liquid falls into the flask beneath, this flask being insert- ed into a vessel of water. Price, with three retort stands and spirit lamp, $6.00. Apparatus for the Condensation of Gases. —(Fig. 571.)—Consists of a tubulated receiver, supported on a retort stand, at one of the necks having a bent tube, which enters one of the necks of a three necked bottle, passing down nearly to the bottom ; the opposite neck having a bent tube for passing the gas into a bell glass. This apparatus, as arranged in the production of nitrogen from chlorine and ammonia, is represented in the cut. The open pipe at the side is supposed to be the beak of a retort in which chlorine is being disengaged. It enters the globular receiver and deposits condensed vapors. Then passing along the bent tube, it arrives at the bottle, b, which is partly filled with diluted liquid ammonia ; passing through the ammonia, it is conveyed away by the pipe, c, into the jar, d. Price, with retort stand, $3.50. Fig. 572. Woolf's Apparatus.—(Fig. 572, as above.)—The most elegant and convenient method of impregnating water with an absorbable gas is by means of Woolf's apparatus, which 104 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. consists of a series of glass three-necked bottles, connected together by bent glass tubes ; the arrangement is shown in the figure. The gas issues from the retort, the neck of which enters the tubulated receiver, and from thence passes into the water in the first bottle and is absorbed; when the water in this vessel is saturated, the gas passes to the next vessel by the glass tube which dips beneath the water; this being saturated, the superabundant gas passes to a third vessel, and so on to any extent that may be required. Price, Woolf's half-pint bottles, - - $0.75. " pint " - - $1.00. " " quart " - each, $1.25. " bent tubes for Woolf's bottles, each, $0.25. " safety " " " " " $0.75. " the whole arranged in a tray, i pint, £6.00. " pint, $0.50. quart, $7.50. Nooth's Apparatus.—(Fig. 573.)— There are various kinds of apparatus for impregnating water with carbonic acid. One of the most elegant and simple is Dr. Nooth's, represented in the cut. The upper vessel, e, is shaped like a funnel contracted at the top, and covered by a stopper, which, however, does not fit tight; the middle vessel, d, fits into the lower one, a, and a communication is made from one to the other by a tube, c, between them, which tube is perforated by holes so small, that gas will ascend through _} them, but water will not descend. The lower vessel, a, contains chalk and water. To use the apparatus, fill b with water, then partly fill E also with water, and put them in their appointed places upon each other ; then pour sulphuric acid into the orifice b, carbonic acid gas will rise, pass through c, and be absorbed by the water in d. When more gas arises than pan be absorbed, its pressure above the surface of the water m d will drive a portion of that water up into the funnel at top, e, and thus the safety of the apparatus is insured CHEMICAL APPARATUS. 105 When the aerated water is required for use, it is drawn off by the tap, f. Price, $15 to $20. Christison's Apparatus for Fig. 571 detecting Poisons.—(Fig. 574.) A is an instrument for reduc- ing the sulphurets of some of the metals by a stream of hy- drogen gas. B is a funnel- shaped tube, for testing mi- nute portions of liquids. C, a tube for reducing a small quantity of mercury. D, a tube for taking up a minute globule of ditto. E, bottle and tube for washing down scanty precipitates or filters. F, apparatus for the distillation of fluids, supposed to contain acids. Price, $4.00 to $5.00. Marsh's Arsenic Apparatus.—(Fig. 575.)— This little instrument is effectual in detecting the most minute quantity of arsenic in any so- lution. It is composed of a bent glass tube, slightly widened at both ends, one area of it being three or four inches longer than the other. Into the shorter arm a small piece of zinc is dropped; a thread should be attached to it so that it shall not quite reach the bottom of the tube. The liquid suspected to contain arsenic has a little sulphuric acid mixed with it, and a portion is poured into the arm B. The stop-cock being open, the liquid will fully occupy A ; but hydrogen gas being formed by the contact of the acid and zinc, this will ascend ; and the stop-cock being closed, it will accumulate. Upon being let off and a light applied to the jet of the cock, the arseniuretted or com- mon hydrogen, as the case may be, will be lighted ; if it be the former, that is, if arsenic be present, it will tinge with a purplish metallic stain a piece of glass held close over it; with common hydrogen, no stain will be perceptible. Price, $2.50. 106 RENJ. PIKE'S, JR., DESCRIPTIVE CATALOG Retort, with Cap and Stop-Cock.— (Fig. 576.)—Retorts with brass cap and stop-cock, bv which the air may be ex- tracted, and anv gas introduced from a bell glass. Price, $1.50. F'g- 577- Glass Blower's Table.— (Fig. 577.)—This consists of a neat table with double bellows worked by a trea- dle, and having a pipe with a jet urging a stream of air through a powerful lamp, supplied with tallow, and is a very convenient article for the use of those who manufacture small articles in glass, such as thermo- meters, test tubes, orna- mental objects, &c. The materials used are glass rods and tubes, of different colors and sizes. The apparatus is merely intended to produce a steady and intense heat, that the glass tubes may be softened in a manner proper for the artist to bend and blow them into the required form. a is a jet of metal, through which the air issues into the flame of the lamp, b. The air is, by means of the treadle, e, forced into the double bellows, d, and driven up the pipe, c, until it issues from the jet. The whole is affixed to a table. The bellows is loaded at the top in proportion to the strength of the blast required. Price, $25.00. Apparatus for Chemical Analysis.—For the greater num- ber of analytical experiments on minerals, very simple appa- ratus will be found sufficient. Tubes, flasks, and evaporating basins, bottles, precipitating glasses, filters, funnels, dropping tubes, a silver, a platinum, and porcelain crucible, each capable of containing from a quarter to half an ounce, small retorts and receivers, a balance, a pair of forceps, a mortar, and a strong spirit lamp, constitute all that is necessary. A blow-pipe and set of test-tubes are of great use. A sepa- rate apparatus is also very desirable for the preparation of sulphuretted hydrogen gas, which is much employed in analytic operations. CHEMICAL APPARATUS. 107 The three figures (Nos. 578, 579, and 580) represent the usual disposition of apparatus employed in preparing, drying, and transmitting gaseous substances over any subject of experiment, when the apparatus requires much care and attention. Fig. .r)-s. (Fig. 578, as above), a, represents bottles, flasks, or re- torts, for producing the gas required; b, a long funnel for introducing acid in small successive quantities, or any other liquid that may be required; c d, balls for intercepting any portion of fluid which may be mechanically suspended in the gas escaping from the bottle ; g, the tube filled with frag- ments of chloride of calcium for drying the gas; f, caout- chouc connectors ; x, wooden stands for supporting the apparatus. ^—5 Fig. 57). T"/i» In Fig 579, the gas is made to act upon I. The assay is often placed in tubes, as G. This figure illustrates the 108 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. arrano-ement adopted when a gas produced by the action of the assay, with the gas from A, is to be transmitted into water, a solution of potassa, or any other substance con- tained in the bottle Z. Fig. 580. Fig. 580 represents a still more complicated arrangement, in which the product obtained, as in the preceding figure, is subjected to still further operations, by the materials in- troduced at S or T. A glass spirit-lamp, mounted on a movable arm, and rod attached to a foot, as represented at Z, is a convenient appendage. Price, $2.50 to $10.00. Fig 581. Fig. 581, one bulb tube. Price, 37i cts. Fig. 582 Fig. 582, two bulb tubes. Price, 50 cts. CHEMICAL APPARATUS. Fig. 583. 109 Five Bulb Potash Apparatus.—(Fig. 583, as above.)— This is a glass instrument with five bulbs, for containing solution of potash to absorb the carbonic acid produced in an analysis, made very light, of the shape of the cut, and also after Liebig's pattern. Price, $1.25. Fig. 584. Fig. 585. Drying Tubes.—(Figs. 584 and 585, as above.)—Bent tubes in which organic bodies are dried, used in organic analysis. Price- 3* to Y5cts- VOL. II.--10 METEOROLOGICAL INSTRUMENTS, THE THERMOMETER. An instrument for determining the exact variations of heat or temperature. The principle on which they are con- structed, is the change of volume which takes place in bodies when their temperature undergoes an alteration. The thermometer consists of a narrow glass tube having an uniform bore, with a bulb at one end, usually filled with mercury, so that expansion or contraction can only take place by the rise or fall of the mercury in the tube; the upper end of the tube is hermetically sealed, within which is a vacuum. The tube is usually fastened to a plate of metal which is graduated to form a scale ; the rising of the mer- cury shows an increase of heat, and the falling a diminution of heat. The usual graduation of the thermometer is accord- ing to Fahrenheit; the 0 is called zero; at 32° water freezes ; at 98° is blood heat; at 212° water boils. Reaumur's scale is used considerably in France; at 0 water freezes, and at 80° water boils. The scale that is used by philosophers in most parts of the world, and that required to be used in the academies of the State of New York by law, is the centigrade scale ; its 0 is at the freezing point, and 100° at the boiling point of water. This scale is frequently gradu- ated on one side of the thermometer tube and Fahrenheit's scale on the other. The thermometer is of extensive use not only to scientific men in their experiments, but is used for regulating the temperature of buildings, hothouses, baths, m the arts, and by navigators in determining the tempera- ture of the water, informing them by its increased cold- ness of the vicinity of land, or when approachino- the Gulf otream by its greater warmth. METEOROLOGICAL INSTRUMENTS. Fair! Cente?[Rfiattrj Common Thermometer.—(Fig. 586.) ~ Je BwfE Zio-fE - 1 —The common case for the thermometer -100- - RO- A is of tin, japanned black, and varying —h I - in size from six to fourteen inches in ^ Z00-E — :' length. ^ E E Price, 6 inch, $0.63. g ' § - 90 — 7 " $0.75. w 190JE 70-t 8 " $0.87. £ — = : — - 10 " $1.00. < JB0 = " 12 " $1.25. < : 80 - 14 " $1.50. 5 EC ._ If with Reaumur's or centigrade scale, | 170-P z___ B0-- 25 cents in addition. a — E - - 160 = - 70 - '-— E - - 150 | "-- - — 1 - 50— Pike's Improved Thcr-™***- F*.587. 140 E E 60 2 mometer (Fig. 587) con- >*—V » ■ E 5_ -- sists of a thermometer I J 130c _: - made as usual, but mount- \ ni 120 E "50 50- ed on a mahogany back, I with polished edges ; the tj r. V1 — E 3__ - ball being protected by a Inljp: i30t 1 no E - -- brass guard, with holes 1 if or slits in it to allow the 111" IMF p 1-40 7 free circulation of air H9(i| n»r HJ"- 100 E - 30-- around the ball. This IJLt »oFH = E"~ style of thermometer is I IB 801- Fjl 90 I 7 -- much approved of and H70|| — \ _-jn E used by many in keeping He<|§ 8oi - _ meteorological observa- Mr 5«P|p' _- ~L 20 - tions. Price, 8 in., $1.00. mi •*»!- 70 E - - " 10 " $1.25. +o|| ■> Pfi' -20 - " 12 " $1.50. . 1 l-v pii E - - " 14 " $1.75. 2'l t GO -E - — = With centigrade scale jonl Fli — E - 10 ■' 25 cents in addition. 10H P k 50 E -10 - If with movable index, '■ y i __n = - and Fahrenheit, and cen- °1 J'I '"• i 40 ■ — ".. - ~~ tigrade scale, 14 inches J M rla i _E 7 ~ long, $2.50. Ill 1 Si j 30 = 1 I tr r.0_ --C-- PIKE S, JR DESCRIPTIVE CATALOGUE. Fig. 590. Ornamental Mahogany Framed Thermome- ter.—(Fig. 588.)— A very neat po- lished frame, inlaid round the scale with ebony, and the ball covered with a brass guard. Price, " 24 inch, $6.00. '• 18 " $2.50. " 12 " $1.75. Mahogany Framed Thermometer, with Glass in front.— (Fig. 598.)—A neat frame of mahogany or rosewood, hav- ing a flat or circular glass in front of the plate, for protecting it from dust and the action of the wea- ther, or otherwise being soiled. Price, best 20 inch, with flat glass, $5.00. " " " " with bent glass, $6.00. " 14 " with flat glass, $2.00. « " " " with bent glass, $2.50. " 12 " with flat glass, $1.75. " " " with bent glass, $2.25. Morocco Case Thermometer.—(Fig. 590.)—This thermome- ter is mounted on a stout metallic plate, and inclosed in a neat morocco case, with hinges and hooks to fasten the case, and ring to suspend it by, is suitable for travellers, may be easily taken out of the case and used for immersing in water, in taking the temperature of springs, &c. The most usual size is eight inches long, but they are also made six, four and a half, and three inches. Price, $1.50. If with ivory scale, 50 cents extra. METEOROLOGICAL INSTRUMENTS. 113 Fig. 591. Self-Registering Thermometer for extreme Heat and Cold. —(Fig. 591, as above.)—In meteorological observations it is of great importance to ascertain the limits of the range of the thermometer in a given period of time, as during a day or night while the observer is absent. The self-reo-isterinof thermometer most generally used for this purpose consists simply of two thermometers, one mercurial, and the other of alcohol, having their stems horizontal; the former has for its index a small steel wire, and the latter a minute thread of glass, having its two ends formed into small knobs. The wire lies in the vacant space of the mercurial thermo- meter, and is pushed forward by the mercury whenever the temperature rises, and pushes that fluid against it; but when the temperature falls, and the fluid retires, this index is left behind, and consequently shows the maximum. The other index of glass lies in the tube of the spirit thermometer immersed in the alcohol ; and when the spirit retires, by depression of temperature, the index is carried along with it, in apparent contact with its interior surface ; but on increase of temperature, the spirit goes forward and leaves the in- dex, which, therefore, shows the minimum of temperature since it was set. As these indices merely lie in the tubes, their resistance to motion is altogether inconsiderable. The steel index is brought to the mercury by applying a magnet on the outside of the tube, and the other is duly placed at the end of the column of alcohol, by inclining the whole instrument. Price,......$4.00. " with long cylindrical bulbs and magnet to move indexes, - $4.50 and $5.00. " mounted singly, mercurial or day ther- mometer, .... $2.50. " " " alcohol or night ther- mometer, .... $2.00. 10* 114 EENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Fig. 592. Figs 593,594. Self-registering thermometer (Fig. 592) for ex- treme heat or cold, with index, extra large size, 12 inches long. Price, $3.00. Thermometer for Sugar Boiling.—(Figs. 593 and 594.)—This consists of a thermometer usually 3 or 4 ft. long, the graduations being confined to a space of about twelve inches long at the upper end of the instrument, allowing the longer part and bulb to be immersed in the boiling sugar. The thermometer is graduated to 270 degrees or upwards, and is mounted in a frame of wood or brass, and having an index which may be set at any degree required for the heat to be maintained at. Price, best brass case instrument, 4 feet long, $7.00. " 3 " " $5.50. " mahogany case instrument, 4 feet long, $6.00. " " " " 3 " " $4.50. " without in- dex, 3 feet long, $4.00. Gothic Mantel Thermometers.—The author ma- nufactures these in a great variety of styles and mounting, bronze, antique bronze, green bronze, gilt, embracing over twenty-five different patterns, most of which are very elegant; and the thermo- meters being manufactured under his immediate superintendence, can be relied on for accuracy. A few of the patterns are represented on the two following pages. METEOROLOGICAL INSTRUMENTS. 115 Fig. 595 Fig. 596. Fig. 597. Price of Fig. 595, 81.75. " " 596. $2.00. " 597, $1.75. Fig. 599, Fi?. 6 0. Price of Fig. 598, $1.37. " 599, $2.00. " " 600, $1.50. 116 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Fig. 601. TiS- 603. Price of Fig. 601, $1.50. " 602, $1.25. " 603, $1.75. THE BAROMETER. The barometer is an instrument for measuring the weight or pressure of the atmosphere, and sometimes called a weather glass. It consists of a cylindrical glass tube, whose diameter is about half of an inch, and its length •hirty-four inches, filled with prepared mercury; one end of the tube is hermetically sealed, and to the open end a reservoir of hard wood is cemented, having a soft flexible leather bag for its bottom, the whole containing the mercury, but not quite full; the atmosphere pressing on the surface of the leather, and causing it to yield to the pressure of the external air, sustains the mercury in the tube to the same height as if exposed to the atmosphere. The tube and reservoir are fixed to a frame of wood, and suspended in a vertical position, having a scale graduated from twenty-seven to thirty one-inches, which is the distance from the surface of the mercury in the reservoir ; the inches are divided into tenths, and in the best instruments there is a vernier moving in a groove in the plate, and subdividing METEOROLOGICAL INSTRUMENTS. 117 the tenths into hun- dredths of an inch ; to the upper edge of the vernier is a small index which is to be placed in a line with the mercury ; a small stud is attached to move the vernier up or down as occasion may require ; the face of the scale and ver- nier are of brass, sil- vered, and in the best instruments they are covered with glass, also having rack work to move the vernier up and down by means of a key in the front of the frame below the scale. Through the under part of the frame passes a screw, with a flat round plate at its end ; by turn- ing the screw, the bag may be so compressed as to force the mer- cury up to the top of the tube, and also to fill the reservoir, which keeps it stea- dy, and prevents the tube from breaking, by the mercury dash- ing against the top, when carried about. The height of the mercury in the tube above the surface of the mercury in the basin is called the 118 BENJ. PIKE'S, JK., DESCRIPTIVE CATAL0 standard altitude, and the difference between the greatest and least altitudes is called the limit or scale of variation The mercury in the barometer tube will subside, till the column be equivalent to the weight of the external air upon the surface of the mercury in the basin, and it is therefore a criterion to measure that weight, and chiefly directed to that purpose. In this country the standard altitude fluctu- ates between twenty-nine and thirty and a half inches. Rules for observing the Barometer.—1. The rising of the mercury presages, in general, fair weather ; and its falling, foul weather; as rain, snow, high winds, and storms. 2. In very hot weather, the falling of the mercury foretells thunder. 3. In winter, the rising presages frost; and in frosty weather, if the mercury fall three or four divisions, a thaw will certainly follow. But in a continued frost, if the mer- cury rise, it will certainly snow. 4. When foul weather happens soon after the falling of the mercury, expect but little of it; and, on the contrary, expect but little fair weather, when it proves fair shortly after the mercury has risen. 5. In foul weather, when the mercury rises much and high, and so continues for two or three days before foul weather is quite over, then expect a continuance of fair weather to follow. 6. In fair weather, when the mercury falls much and low, and thus continues for two or three days before the rain comes, then expect a great deal of wet, and probably high winds. 7. The unsettled motion of the mercury denotes uncertain and changeable weather. 8. You are not so strictly to observe the words engraved on the barometer plate, as the rising or falling of the mercury, for should it stand at much rain, and then rise to changeable, it presages or foretells fair weather, although its continuance is not to be depended on so much as if the mercury were higher. But when it stands at fair, and sinks to changeable, it indicates bad weather, though not so much in proportion as if it had sunk lower. Therefore, in order to pass a right judgment of the weather, the point where the mercury stands is not so much to be regarded, but it should be par- ticularly considered whether the mercury is actually in a rising or falling state. For its minutest alterations should be accurately attended to for the purpose of forming a rio-ht judgment respecting the weather expected to succeed. When Ave would observe the barometer with accuracy, METEOROLOGICAL INSTRUMENTS. the tube should be first shaken bv gently tapping the front of the frame with the back part of the fingers, from three to five times. Plain Barometer.—(Fig. 604.) —Barometers are mounted in a variety of styles ; the figure re- presents one in a neat polished mahogany frame, having a ther- mometer on one side of the scale, and a screw at the bottom of the reservoir or cistern of the barome- ter for the purpose of forcing the mercury up, which, filling every part of the tube, renders the in- strument portable, and may be carried in a horizontal or other position in transportation. Price, $10.00. Barometer with Glass Door.— (Fig. 605.)—This has a neat frame of mahogany or rosewood, with round or square top, and having a small door with glass in front of the scale, with thermometer and portable screw, as described in the preceding figure. Price, - - $11.00. " with vernier subdividing the graduations to 100 of an inch, $12.00. 1 120 ' ,„ INSCRIPTIVE CATALOGUE. BENJ. PIKES, JR., DESCKirn Fig. 606. Fig. 607. Best flat front Barome- ter— (Fig. 606.)— 1 he best flat front mahogany case barometer having vernier and glass door, with large thermometer in the body of the case, having a long cylindrical bulb to the tube, exposing thereby a large surface to the atmosphere, graduated to Fahrenheit and centigrade scales, and covered with glass, porta- ble screw at the bottom, and the case highly po- lished. Price, $16.00. Best Circular Front Rosewood Barometer. — (Fig. 607.) — The most elegant barometer is the circular front rosewood mounted instrument, with large thermometer in the body of the case, having Fahrenheit and Reaumur's, or centigrade scales, and the tube having a long cy- lindrical bulb, the scales co- vered with circular glasses; vernier to the scale hav- ing rack motion, which is°moved by a key in the front of the case below the scales. The case of this instrument is highly finish- ed and polished, and be- sides being an instrument of great utility is quite ornamental. Price, $22,00 and $25.00. METEOROLOGICAL INSTRUMENTS. 121 The Mountain Barometer.—(Fig. 608, next page.)—A very important property of this valuable instrument is that of determining heights, and its accuracy is inferior to no other mode; on this account it is not only very useful to surveyors, but highly interesting to philosophers, scientific men, &c. It consists of a tube, &c, as described in the first article under this head, having a smaller reservoir for the mercury, which is inclosed in a round case, about one and a half inches in diameter, at the upper part of which an opening, of about one quarter of the circumference of the case, and twelve inches long, is made, the sides of which are inclined towards the tube, on one of which the barometer scale is attached, which ranges from twenty to thirty-one inches, divided to twentieths of an inch, and hav- ing a vernier sliding on the scale, subdividing these into five hundredths of an inch ; to the upper edge of the vernier there is a small index to be set in a line with the mercury ; on the other side of the opening there is a delicate thermo- meter, which may be detached if required ; that part of the case to which the scales are attached is surrounded with a brass tube, having an aperture cut in it corresponding to the opening in the case ; there is also a narrow opening at the back through the case and tube, for allowing the light to be seen through, and more accurately observing the surface of the mercury ; the tube may be turned round so as to close these openings entirely, and is kept on by a brass cap at the top, into which a ring may be screwed for suspending the instrument. As the reservoir in this instrument is small, and any con- siderable depression of the mercury would considerably alter the level therein, a correction is made in the best instruments, for which purpose the reservoir is accurately measured, and the contents of one inch, compared with one inch of the tube, ascertained, which is to be subtracted from the height when the mercury falls below thirty inches, which amount of correction is engraved on the brass cap. The reservoir is inclosed in a brass case, having a portable screw, over which the brass cap is screwed. This barometer has been used by many scientific gentlemen in their observations, and is the least liable to derangement of any used for mea- suring heights; is very light, and may be inverted, and with care used as a walking stick in ascending heights. The density or weight of the atmosphere is not equal, but VOL. n.—11 BENJ. PIKE S, JR., DESCRIPTIVE CATALOGUE. Fig. 639. the higher we ascend the rarer it be- comes? At 31 inches a fall of one- tenth of an inch indicates a height of 82 feet • at 30 inches, 85 feet; at 29 inch- es 87 feet; at 28 inches, 91 feet; at 27 inches, 94 feet; and at 26 inches, 98 feet; for every tenth of an inch the ' falls. $20.00. with corrections for level in reservoir, and extra finish, $25.00. mercury Price, Pike's Mountain Barometer for Aca- demies.—{Fig. 608.)—This is an instru- ment similar in its construction to the preceding one, but of a larger make ; the case being two inches in diameter, hav- ing a brass cover to the scales, and the reservoir of mercury being so large as to make it unnecessary to use any cor- rection for the level, and is inclosed in a brass case with portable screw covered with a cap screwing on. The barometer scales extend to twenty-five or twenty-six inches, which will allow of the measurement of a height of 4000 feet or over. This is a stout and well made instrument, the brass work highly polished, and the demand for them has enabled the maker to sell them at a very low rate. Price, - - - Si 0.00. " with vernier, $12.00. Standard Barometer.—(Fig. 609.)— This consists of a tube of unusually large size filled with mercury, and inverted in a large glass reservoir also containing mercury, the top of which is exposed to the atmosphere, and covered by a wooden cap, through which a pointed steel rod passes, fastened to a projection METEOROLOGICAL INSTRUMENTS. from the lower part of the barometer scale, which reaches to the surface of the mercury. The scale is fastened to the case by four screws passing through long holes covered by springs, allowing the scale and point attached to be moved up or down, and set at any time in exact contact with the surface of the mercury, by a brass knob near the centre of the scale. From the end of the steel point the scale commences, and is graduated to thirty-one inches, subdivid- ed as usual, and having a vernier with index ; the mounting consists of a neat mahogany case, well polished. This is a valuable instrument where it can be set up by a maker, but cannot usually be transported without being put out of order, requiring to be kept in a vertical po- sition, but may be sent unfilled, and requires but little skill to fill and immerse in the mercu- ry, directions for which will be furnished. Price, $22.00. Marine Barometer.—(Fig. 610.)—The ba- rometer is of great use to the mariner, who is thereby enabled to foresee and prepare for sud- den changes of weather. The marine barome- ter consists of a glass tube with reservoir of mercury, as in the usual barometer, but having a portion of the lower part con- tracted to a very fine bore, to prevent the unsteadiness of the mercury, which would other- wise be occasioned by the roll- ing of the ship. The tube is inclosed in a mahogany case, square in front, and rounded at the sides, and enlarged somewhat at the upper end for receiving the scales, for which there is an opening with the scales fixed on the sides, which are graduated as in any other ^^m barometers; this opening is (E~~ covered by a small door, on the 124 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Fig. 611. inner side of which is fixed a thermometer. The reservoir is inclosed in a brass case, having a portable screw beneath. The barometer is suspended in a vertical position, by a brass arm and gimbals, attached by thumb-screws to the side of the case, just above the middle, which allows the barometer to hang always in a vertical position, however the ship may roll; attached to the arm there is a stout circular plate, having holes for screws, to fasten the instrument to any part of the cabin of the ship ; the arm is jointed at the plate for the pur- pose of turning the arm and ba- rometer up, that it may be out of the way when not required in use. Price, - - - $20. fine finished, $25. Troughton's Mountain Barome- ter.—(Fig. 611.)—The employ- ment of the barometer for the determination of heights, has caused it to become an interesting instrument to the philosopher and traveller ; and many attempts have been made to improve it, and render it portable, that it may be conveyed from place to place, without much inconveni- ence or risk. The adjoining figure represents the portable barome- ter, as constructed by Mr. Trough- ton. In the brass box, A, which covers the cistern of mercury near the bottom of the tube, are two slits made horizontally, precisely similar and opposite each other, the plane of the upper edges of which represents the beginning of the scale of inches, or zero of the barometer. The screw, B, at the bottom, performs a double office; first, it is the means of adjusting the surface of the mer- METEOROLOGICAL INSTRUMENTS. 125 cury in the glass cistern to zero, by just shutting out the light from passing between it and the upper edges of the above-named slits; and secondly, by screwing it up, it forces the quicksilver upwards, and by filling every part of the tube, renders the instrument portable. The divided scale on the upper part, is subdivided, by the help of a vernier, to the one thousandth of an inch. The screw, c, at the top, moves a sliding piece, on which the vernier scale is divided, the zero of which is at the lower end of the piece. In taking the height of the mer- cury, this sliding piece is brought down and set nearly by the hand, and the contact of the zero of the vernier with the top of the mercurial column is then perfected by the screw, c, which moves the vernier the small quantity that may be required, just to exclude the light from passing between the lower edges of the sliding piece, and the spherical surface of the mercury. The barometer is attached to the stand by a ring, in which it turns ronnd with a smooth and steady motion, for the purpose of placing it in the best light for reading off, &c. ; and the tripod stand, when closed, forms a safe and con- venient packing case for the instrument. A thermometer is always attached to the lower part of the barometer, to indicate its temperature, while another, detached from the instrument, is employed at the same time, to show the temperature of the surrounding air. The barometrical method of determining differences of level, is founded upon the principle that the strata of air decrease in density, in a geometrical proportion, when the elevations above the surface of the earth increase in an arithmetical one. Therefore, from the known relation be- tween the densities and the elevations, we can discover the elevations by observations made on the densities by means of the barometer. Price, $50.00. The Wheel Barometer.—(Fig. 612, next page.)—The wheel barometer consists of a glass tube, closed at one end, and the other open, and bent upwards, and of thirty-two inches or upwards in length exclusive of the bend ; the tube is entirely filled with prepared mercury, which, on placing in a vertical position, will subside in the closed end of the tube and rise in the open tube that is bent upwards, until the difference in the levels will be equal to the height of a 11* 126 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Fig. 612. column of mercury which will balance the weight of atmosphere; so that any change in the pressure of the atmosphere, will have an equal effect on the mer- cury at the closed end and at the open end ; and thus, through whatever space the mercury may rise in the closed end, it will be de- pressed to the same extent in the open end ; the tubes at these parts being of pre- cisely the same diameter, while between them the tube is contracted. Upon the surface of the mercury in the open end floats a glass weight, suspended by a silk thread over and around a brass pulley, to the other end of which is attached another weight, not quite as heavy, acting as a counter- poise to the former. The axis of the pulley passes through the frame and centre of the dial plate, and carries a blued steel hand, which re- volves as the pulley turns round. The weight on the surface of the mercury being nearly supported by the counterpoise, rises or falls freely as the surface of the mercury on which it floats is elevated or depressed by the weight of the air. If the circumference of the wheel be one inch, then one entire revolution of the wheel will correspond to an METEOROLOGICAL INSTRUMENTS. 127 alteration of level amounting to one inch in each tube, or two inches in the height of the barometric column; and as the dial plate may be from twenty to thirty-six inches in circumference, five to nine inches on the graduated plate corresponds to one inch of the column, which is divided into one hundred parts, each of which is distinctly perceptible. The frames are usually of mahogany, the best ones of rosewood, highly polished; the dial-plate is from six to twelve inches in diameter, and elegantly engrave! and silvered, and is covered by a brass ring containing a convex circular glass ; also a thermometer capable of b/ng de- tached, having a separate frame sunk into the body of the frame of the instrument, and covered with a glass; the thermometer tube having a long cylinder, instead of a round ball, for containing the mercury, thus exposing a greater surface to be acted on by the atmosphere. In the back of the frame of the instrument is a cavity covered by a hinged door, within which the tube and fixtures are enclosed. There is usually an index of polished brass, working on the dial plate of the best instruments, movable by a key below the dial, and serving to indicate the position of the hand, when last observed. The mode of fitting up this in- strument gives it an elegant appearance as a piece of furniture. Fi» 6ia Price of 8-inch, in mahogany frame, $12.00. ^ 10-inch, " " $15.00. " 8-inch, best rosewood, $15.00. 10-inch, " " $18.00. 12-inch, " " $25.00. Prognosticator, or Storm Glass.—(Fig. 613.)— A new curious instrument, formed of different com- positions, which will indicate the weather; particu- larly high wind, storm, or tempest. It will be preferable by sea and land, being portable, and will be found to be very exact and useful. Rules to be observed.—1. If the weather is to be fine, the substance of the composition will remain en- tirely at the bottom, and the liquid will be very clear. 2. Previous to changeable weather for rain, the substance will rise gradually, and the liquid will be very clear, with the appearance of a small star in motion. 12S BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 3. Before a storm or extraordinary high wind, the sub- stance will be partly at the top, and will appear m form of a large leaf; and the liquid will Le very heavy, and in a fer- mentation. This will give twenty-four hours notice before the weather changes. 4 In winter time, generally the substance will he rather hi<>-her particularly in snowy weather or white frost; the composition will be very white, with white spots in motion. 5. In summer time, the weather being very hot and fine, the substance will be quite low. Price, $1.25. Fig. 6U. Differential Thermometer.—\Fig. 614.)—This instrument consists of a long glass tube, twice bent at right angles, having a bulb at each extremity. The tube contains a quantity of sulphuric acid, tinged with cat mine The instrument is furnished with a scale of 100 equal parts, and is fixed upon a wooden support. Both the bulbs of the instrument being exposed to the s ime temperature, it is not in the least affected ; but as soon as one of the bulbs is exposed to a higher temperature than the other, the difference between them is deli- cately shown by the falling of the colored fluid below the bulb, which is most heated. This in- strument not being affected by the variations of atmo- spherical pressure, nor by fluctuations of temperature in the atmosphere, it is admirably fitted for experiments on ra- diant heat. Price, $1.50. Howard's Differential Thermometer.—(Fig. 615, next page.)—This instrument is a modification of the last, and considered by some as more convenient, the difference con- sisting in the balls being placed the one above the other. Price, $1.50. METEOROLOGICAL INSTRUMENTS. 129 Fig. 615. Fig. 61G. The Oat Beard Hygrometer.—(Fig. 616.)— This hygrometer is formed of the beard of the wild oat, one end of which is fixed in a small column, and usually placed in the centre of a round brass case, covered with a glass ; the other end has a small index attached, usually made of a slender piece of light wood. Within the case there is a dial, divided into equal parts and numbered from 0 to 30 each way, and on one side the word Dry, and on the other Damp. In the sides of the case there is a num- ber of holes, in order that the atmosphere may have free access to the interior of the instrument. There is a spring in the back of the case, attached to the column, by which the index may be set at 0 on the dial. When this instrument is exposed to dryer or moister air, the small index, by turning round, either in one direction or the other, indicates the state of the atmosphere. This is a simple and useful instrument for ascertaining the comparative dryness or dampness of different apart- ments, beds, &c, but it is not suited for meteorological ob- servations. Priee, $2.50. 130 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Fig. 617. Satisimre'i, Hygrometer (Fig. 617) consists of a human hair prepared by boiling it in caustic lev; one end of the hair is fixed to the upper part of a frame, usually about ten inches long, and four wide, and the other end passes round the axis of a small grooved wheel or pulley, the axis of which carries a counterpoise by which the hair is kept stretched, and an index which moves over a graduated arch ; on the upper part of the scale there is usually fixed a thermo- meter. When the surrounding air becomes more humid, the hair absorbs an additional quantity of moisture, and is elongated ; the J counterpoise consequently descends and turns the pulley, whereby the index is moved towards the one hand or the other. On the contrary, when the air becomes dryer the hair loses a part of its humidity, and is shortened. The counterpoise is consequently drawn up, and the index moves in the opposite direction. Price, $5.50. Hygrometers by Condensation.—The two preceding hygro- meters are constructed on the principle of absorption, and for meteorological researches are of but little use. Those remaining to be described are constructed on the principle of condensation, and form valuable instruments for the me- teorologist, of which Mason's is the simplest and most modern construction. In order to give an idea of the general prin- ciple on which they depend, let us conceive a glass jar, hav- ing its sides perfectly clean and transparent, to be filled with water, and placed on a table in a room where the tempera- ture is, for example, 60°; the temperature of the water being the same as that of the room. Let us next suppose pieces of ice, or a freezing mixture, to be thrown into the water, whereby the water is gradually cooled down to 55, 50, 45, &c, degrees. As the process of cooling goes on, there is a certain instant at which the jar loses its transpa- rency, or becomes dim; and on attentively examining the phenomenon, it is found to be caused by a very fine dew, or deposition of aqueous vapor on the external surface of the vessel. The precise temperature of the water, and conse- quently of the vessel, at the instant when this deposition begins to be formed, is called the dew point, and is capable of being noted with great precision. Now this temperature METEOROLOGICAL INSTRUMENTS. 131 is evidently that to which, if the air were cooled down under the same pressure, it would be completely saturated with moisture, and ready to deposit dew on any body in the least degree colder than itself. The difference, therefore, between the temperature of the air, and the temperature of the water in the vessel when the dew begins to be formed, will afford an indication of the dryness of the air, or of its remoteness from the state of complete saturation. But the observation which has now been described is ca- pable of affording far more interesting and precise results than a mere indication of the comparative dryness or mois- ture of the atmosphere. With the help of tables of the elastic force of aqueous vapor at different temperatures, it gives the means of determining the absolute weight of the aqueous vapor diffused through any given volume of air, the proportion of vapor existing in that volume to the quan- tity that would be required to saturate it, and of measuring the force and amount of evaporation. Daniell's Hygrometer.—(Fig. 618, next page.)—The cut represents Daniell's hygrometer, in which a and b are two thin glass balls of one and a quarter inch in diameter, connected together by a tube, having a bore of about one-eighth of an inch. The tube is bent at right angles over the two balls, and the arm, b c, contains a small thermometer, d e, whose bulb, which should be of a lengthened form, descends into the ball, b. This ball, having been about two-thirds filled with ether, is heated over a lamp till the fluid boils, and the vapor issues from the capillary tube, /, which terminates the ball, a. The vapor having expelled the air from both balls, the capillary tube,/, is closed hermetically by the flame of a lamp. This process is well known to those who are accustomed to blow glass, and may have been known to have succeeded, after the tube has become cool, by revers- ing the instrument and taking one of the balls in the hand, the heat of which will drive all the ether into the other ball, and cause it to boil rapidly. The ball, a, is now to be covered with a piece of muslin. The stand, g h, is of brass, and the transverse socket, i, is made to hold the glass tube, in the manner of a spring, allowing it to turn and be taken out with little difficulty. A small thermometer, k I, is in- serted into the pillar of the stand. 132 benj. pike's, jr., descriptive catalogue. Fig. 618. The manner of using the instrument is this :—After hav- ing driven all the ether into the ball b, by the heat of the hand, it is to be placed in an open window, or out of doors, with the ball b so situated as that the surface of the liquid METEOROLOGICAL INSTRUMENTS. 133 may be upon a level with the eye. A few drops of ether are then to be poured upon the covered ball. Evaporation immediately takes place, which, producing cold upon the ball a, causes a rapid and continuous condensation of the ethereal vapor in the interior of the instrument. The con- sequent evaporation from the included ether produces cold in the ball b, the degree of which is measured by the ther- mometer, d e. This action is almost instantaneous. The thermometer begins to fall in two seconds after the ether has been dropped. A depression of thirty degrees is easily produced, and sometimes the ether boils, and the thermo- meter falls below 0° of Fahrenheit's scale. The artificial cold thus produced causes a condensation of the atmospheric vapor upon the ball, b, which first makes its appearance in a thin ring of dew, coincident with the surface of the ether. The degree at which this takes place is to be carefully noted. A little practice may be necessary to seize the exact moment of the first deposition, but certainty is very soon acquired. It is advisable to have some dark object behind the instru- ment, such as a house, or a tree, as the cloud is not so soon perceived against an open horizon. The depression of tem- perature is first produced at the surface of the liquid where evaporation takes place, and the currents which immediately ensue to restore the equilibrium are very perceptible. The bulb of the thermometer, d e, is not quite immersed in the ether, that the line of greatest cold may pass through it. The greatest difference that Mr. Daniell has observed in the course of four months' daily experiments between the ex- ternal thermometer, k I, and the internal one, e d, at the moment of precipitation in the natural state of the atmo- sphere, was twenty degrees. In very damp weather the ether should be slowly dropped upon the ball, otherwise the descent of the thermometer is so rapid as to render it impossible to be certain of the degree. In dry weather, on the contrary, the ball requires to be well wetted more than once, to produce the requisite degree of cold. It is almost superfluous to observe, that care should be taken not to permit the breath to affect the glass. With these pre- cautions the observation is simple, easy, and certain. By combining the rise and fall of the barometer with the effects of this instrument, we learn to modify their results, and by so doing can hardly be deceived in the weather for many hours in advance. The indications are to be corrected VOL. II.—1 - 134 BENJ. PIKE S, JR., DESCRIPTIVE CATALOGUE. according to circumstances in the following manner:—In summer time, when the diurnal variations of temperature are great, regard is to be had to the time of day at which the experiment is made. In the morning, supposing the differ- ence between the temperature of the air and the constituent temperature of the vapor to be small, it is to be recollected, that the accession of heat during the day is great, and that the difference will therefore probably increase. If the point of condensation should at the same time be lowered, it is in indication of very fine weather. If, on the contrary, the heat of both should increase with the day in nearly equal pro- gression, rain will almost infallibly follow, as the heat of the air falls with the setting sun. In showery weather, the in- dications of this instrument vary rapidly three or four de- grees ; and a person making observations at short intervals of time, may easily predict the approach of a storm. Price, $14.00. METEOROLOGICAL INSTRUMENTS. 135 MASON'S HYGROMETER. The use of this instrument (Fig. 619, next page) in the sick chamber will be at once evident, as a fire kept up in a closed room naturally dries the air which the patient has to breathe, and it soon becomes either more detrimental or bene- ficial in many diseases of the lungs, skin, or intestinal canal. It is the duty of the medical attendant to point out those conditions of the body which will be benefited or injured by atmospheric influences, and suggest the means by which this can be obviated as far as art will allow ; for in many cases life depends upon the temperature, state of dryness, or hu- midity of the climate or room in which an individual resides, which condition of the air it is the office of the instrument to constantly register, and show, by mere inspection. If the apartment is too dry, which is frequently the case in frosty weather, it will be necessary to maintain sufficient evaporation from a tea urn, or other convenient apparatus, while the hygrometer points out when the proper degree of humidity has been attained ; the urn is then removed, and may be brought into the room again when required. On the contrary, if the air be required remarkably dry, it may be ren- dered so, either by raising the temperature of the room, or re- sorting to those substances which absorb vapors most rapidly. Thus with the aid of this instrument (as it indicates both the temperature, dryness, and humidity of the air), an arti- ficial locality may be produced by very simple and easy means ; and those, whose circumstances, avocations, or family ties, prevent them from seeking a climate suited to their peculiar constitution, can, to a very great extent, obviate the necessity by the assistance of the instrument now submitted to the public, the desideratum of which has been long felt, and its prospective uses fully appreciated by the reflecting portion of the profession. If the air be very dry, the difference between the two thermometers will be great; if moist, less in proportion; and when fully saturated, both will be alike. For general purposes, it is only necessary to place the instrument in a retired part of the room away from the fire, and not exposed to the open doors or passages ; but for nice experiments, the observation should be always made in the open air and in the shade, taking especial care that the instrument be not influenced by the radiation of any heated bodies, nor any 136 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Fig. 619. METEOROLOGICAL INSTRUMENTS. 137 currents of air. Should the wind be strong upon the instru- ment, the " degrees of dryness observed," multiplied by two, gives the " absolute dryness" (the " excess of dryness" being omitted in the calculation), bec.uise a strong current of air makes the instrument indicate the excess of dryness, which is necessary to be added in a calm atmosphere. If the absolute dryness of an apartment be required, the instrument must be placed in the shade and the dew-point found, which, subtracted from the temperature of the apart- ment, will give its absolute dryness. The reason is obvious, and arises from this law, namely, that air has its dryness doubled for every increase of temperature corresponding to 21° of Fahrenheit's thermometer, and in proportion for all intermediate temperatures. It will detect the dampness of an apartment or bed. The facility of registering meteorological observations by this instrument, will probably induce many to avail them- selves of its use, and tend to enlarge that branch of science. In regulating the hygrometrieal state of the air in hot- houses, green-houses, &c, as well as in manufactories, ware- houses, malting-houses, and in the laboratory of the chemist, its use will be duly appreciated. The advantages it offers at sea cannot be too forcibly pointed out. The objections made by naval men to the barometer, leaving them in doubt whether to expect wind or rain by the fall of the mercury, would in a great measure be obviated by the joint observation of the hygrometer, because, if it indicate a relative degree of dryness, wind alone may be expected; if the contrary, then rain, or rain with wind, follows. N. B.—The silk which covers the wet bulb, and thread which conveys the water to it, requires renewal about every month, and the fountain to be filled, when requisite, with distilled water, or water that has been builed and allowed to cool, by immersing it in a basin of water till the aperture only is just upon the surface, and the water will flow in. If the hygrometer is placed out of doors in frosty weather, the fountain had better be removed, or the freezing of water within it may break it; in this case a thin coating of ice may soon be formed on the wet bulb, which will last a con- siderable time, and may be renewed when requisite. Price, ------- $3.50 to $5.00. " best article in rosewood case, lined with velvet, $7.00. 12* 138 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. TABLES FOR THE USE OF DR. MASON'S HYGROMETER. TABLE OF DEGREES. Mason's Degrees-f-excess X 2=abso- Leslie's Hygro- lute dryness. Hygrome- meter. ter compared with Mason's. Degrees of Excess of Absolute dryness dryness to be dryness observed. added. existing. 0 0.0 0.0 0 (15 0.0S3 1.1R6 3 1 0.166 '.'.332 6 15 0.2495 3.499 9 l2 0.333 4666 12 25 0.4165 5 833 13 3 0.5 M> 7.0 18 3.5 n.583 8.166 21 4 0.666 9.a32 21 4.5 0 7495 10.499 '-7 5 0.833 11.666 30 55 0.9163 12.833 33 6 10>0 140 3.3 65 1.083 15.166 39 7 1.16(1 16.332 42 7.5 1.2493 17.499 45 8 1333 18.666 48 8.5 14163 19 833 51 9 1 ..".Oil 21.0 54 9.5 1.583 22 166 57 10 1.663 23.332 60 |o.5 1.7493 21.499 63 11 1.833 25.666 66 11.5 1.9165 26.833 69 12 2.0U0 £8.0 72 \»5 2.083 29.163 75 13 2.166 30..i32 78 13 5 2 2495 31499 81 11 2.333 32.666 81 11. .3 2.4165 33.833 87 15 2.5011 33.0 91 155 2.583 35.163 93 l(> 2666 37.332 93 16.3 2.7495 38 499 99 17 2.833 39.601 102 17.5 2.9165 40.833 105 18 3 0(M 42.0 1'8 K5 3.033 43.166 111 19 3.166 41.332 114 r.i.5 3 2495 45499 117 21 3.333 46.666 12) 2 .5 3.4165 47.833 123 21 3.50) 49.0 126 21.5 3.583 5016S 1-29 22 3666 51.332 132 2.'.5 3.7195 52499 133 . — = o The comparison of Mr M .son's with the *Dew Point Hygrometer, and of Sir ,'ohs Leslie's, will be seen in the same line of the 1st, 3d, and 4th columns of the rv V.. ' *ofessor Daniell's Hygrometer is registered by the 3d column. METEOROLOGICAL INSTRUMENTS. 139 TO FIND THE QUANTITV OF VAPOR BY WEIGHT EXISTING IN THE ATMOSPHERE. PROBLEM.—The temperature of the atmosphere in the shade, and of the Dew Point, being given, to find the quantity of vapor in a cubic foot of air. If the temperature of the air and the Dew Point correspond, which is the case vvheu both thermometers are alike, and the air conse- quently saturated with moisture, then in the table of qvantity oppo- site to the temperature will be found the corresponding weight of a cubic foot of vapor expressed in grains. Example —Let the temperature of the air be 70 deg. Fah.. ai:d the Dew Point the same—then opposite the temperature you have the weight of a cubic foot of vapor—8.392 grains. But if the temperature of the air be different from the Dtw Point, a correction is necessary to find the exact weight Example.— Suppose the Deu- Point be 70 deg. Fah. as before, but the temperature of the air in the shade be 80 (leg., then the vapor has suffered an expansion due to au excess of 10 deg , which requires a correction. We liud in the table of corrections for 10 deg. 1.0208. Then divide 8.392 grains at the Dew Point, viz. 70 deg. by the correction corresponding to the degrees of absolute dryness, viz. 10 deg , and you have the actual weight of vapor existing. 8.3920 Examplk.-------8.221 grains existing, which subtracted from 1.0208 weight of vapor, corresponding to the temperature of 80° Fah., gives the number of grains required for saturation at that temperature. Example.—11.333 grains at the temperature of 80 deg. Fah. 8.221 graiiis contained in the air. 3.112 grains required for saturation. To find the relations of these conditions on the natural scale of humidity (complete saturation being 1.000). divide the weight of vapor at the Dew Point by the weight at the temperature of the air, the quotient gives the parts of 1.000 the degrees of saturation. 8.392 grains at the Dew Point—70 Example.----- =.740 deg. of humiditv 11.333 grains at the temp, of the air 80 saturation being 1.0J1 The principles of these calculations will be found iu Professor Daniell's Meteorological Essays—Mr. Anderson's Essays on Hygro- metrv, in the Edinburgh Encyclopedia, vol. XL, and in the Edin- burgh Journal of Scieuce, vol. VII.. page 43, in an excellent article ou the Dew Point Hygrometer, by Mr. Foggo—from which the tahle of corrections has been partly subtracted. The Table of Quantity by Weight has been taken from Professor Daniell's Work on Meteor ology ; °o which the reader is referred for further particulars. 140 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. TABLE OF QUANTITY, Showing the Weight in Grains, of a Cubic Foot of Vapor, at different Temper* = • turc-, from 0 to 95 t ahreuheit. Temp Weight in Grains Temp Weight in Grains. 0 8.36 0 892 0.9-8 0.963 0.999 I (31 1.069 1.104 1.131 1.173 1.2 8 1.-54 1.3.(8 i.t« 1451 1.497 1.511 1586 1.631 1.683 1757 1 825 1.893 24 1.931 -5 «.< 28 26 2. 96 27 2.163 28 *. 29 29 2 295 3) 2 351 31 2451 32 ■2.539 33 2.630 31 •2.717 35 2.805 36 a 892 37 2.979 38 3.066 39 3 153 41 3.231) 41 3 371 42 35 2 43 3.633 41 3763 45 :v893 43 4.1.22 47 4 151 Temp Weight in Grains. 4. 79 44 7 4.335 4684 4.832 5 (). 3 5.173 5.312 5.xl 5 679 5.8 8 6. 43 6 222 6 399 6 575 6.794 7.ul3 7 230 7.417 7.632 7.899 8 133 8 3J2 8.658 Temp 72 73 71 75 76 77 78 79 80 81 P2 83 81 83 83 87 88 Weight in Grains. 8924 9 199 9484 9 73i 10 107 10 387 10 699 11016 U331 11 665 I 005 12 334 12 713 13 031 13 458 13877 U23i 146(3 1.05 13 432 13 78. In.186 16 593 I7.i09 TABLE OF CORRECTIONS, To be used when the Term of Dtiosition, or Dtv roivt, diflers fi' in the Tempe rature of the Air in the Shade. Diff. Correction Diff Correction Diff Correction. Diff Correction of _;_ of -;- of —.— of • —:— Temp Temp Temp. Tern p 0 o oroi 13 1.0271 n" 1H542 39 1.0813 1 10020 14 1 0291 , 27 1 0561 41 10834 2 10'41 15 1)312 1 28 1 1-583 41 1 (854 3 I. .062 16 l.«>333 II -9 1.06 4 42 1X875 4 1 0083 17 1 1354 ! 30 1 06-25 43 l.ntS96 5 1 01..4 18 11.375 [• 31 1(616 41 1(917 6 I 1.12.5 19 l.i 396 32 1 0667 45 1.0937 7 10146 •20 H4l7 ii 33 H687 46 1 0958 8 I 0167 21 1 0437 !| 31 1 <7«8 47 1U979 9 10187 \ii 1.04 >H i 35 1 .729 43 l.lllMI in I 0 08 "3 ! 10479 3; I t7-">) 49 1 l'lal 11 1 02 -9 21 1.1 5 0 37 1 i 771 [ 50 1 1012 12 1 0230 1 25 1 0521 '■ 3S 1 . 792 51 1 1 1..62 1 52 |l I I S3 Rule. To find the weight of moisture in a cubic foot of air at any tia.e Divide the we ght in Grains, found opposite the Temperature, corresponding to the Dew Point at the time, in the Table of Quantity, by ihe Correctiot found opposite to Difference of Temperature in Tab e of Corrections, corresponding to the absolut* dryness existing at the time. METEOROLOGICAL INSTRUMENTS. 141 Fig. 620. Jones's Hygrometer. — (Fig. 620.)—This instrument is the same in principle as Daniell's hygrometer, but simpler in its construction, more compact, and less expensive. The mercurial thermometer, with its tube at A B, is bent so as to bring its cylindrical ball, C, parallel with, and a little distance from its stem. The bulb is one inch long, and is terminated by a flat- tened surface, D, of black glass, which projects a little beyond the sides of the bulb. The bulb below the flattened surface is covered with black silk. The instrument is supported on the wire, E F, which is attached to the scale by a pivot, that allows the black surface to be inclined to the light. When used, the temperature of the air is first noted ; then ether is poured on the silk cover of the bulb ; and the condensation of the dew is seen on the black extremity of the bulb. Price, $5.00. Leslie's Thermometric Hygrometer. —(Fig. 621.)—A thermometric hy- grometer is an instrument formed from a differential thermometer, by covering one of its balls with tissue paper or black silk. Being kept moist with water, the evaporation produces cold, and that in a degree exactly accordant with the state of dryness in the atmosphere, a b, is the differential thermometer; the ball, b, being naked, that at a, cover- ed ; c, is a vessel of water, which has a few filaments of cotton that reach from the liquor in Fig. 621. 142 BENJ. pike's, jr., descriptive catalogue. it to the covered ball. This acts as a syphon, and keeps the ball moist. The graduated scale shows the degree of evapo- ration. When this hygrometer stands at 15°, the air feels damp, from 30 to 40° we reckon it dry, from 50 to 60° very dry, and from 60° upwards we should call it intensely dry. Price, $5.00. fig- 622. Conical Rain Gauge.—(Fig. 622.) —The rain gauge is a simple cone of copper, of a given shape and capacity, which is placed in any situation where it will receive its due proportion of rain. It is usually placed in a piece of wood, bevelled out to fit the cone, and fastened to a post about eight feet high; the cap is placed in the cone with its base downward. However closely it may fit, by being pressed into it, there will still be sufficient room left between it and the sides of the gauge to permit the water to pass to its bottom. Immediately after every shower, or fall of rain, the water must be measured, and the contents registered and then discharged. On this will depend the accuracy of the account; for, from the construc- tion of the gauge, the degrees of the scale near its bottom being the largest, small quantities may be measured with greater accuracy by this than by the gauges commonly used. The cap is intended to prevent evaporation before the measurement is made, should that be accidentally delayed. The measurement is made by putting down to the bottom of the gauge, the point of the measuring stick, and applying the distance between it and the water-mark to the scale. The graduation of the scale is by hundredths of an inch for the first three-tenths of an inch, and above that by tenths and half-tenths. The intermediate distances may be measured by the eye, and set down in decimals. When showers or rains of short duration fall, it will be well to note the A. M. and P. M., with the hours between the beginning and end prefixed, in order that the time may be compared with that of observations made at other places. If the rain continues for any length of time, the observations should be METEOHOLOGTCAL INSTRUMENTS. 113 made at suitable intervals before the water rises in the gauge. It is important that the measure be taken without delay after every fall of rain, as experience has proved that the water in the gauge will soon become diminished by the rising along the inside of the gauge by capillary attraction, and then become dissipated by evaporation. The usual precaution must be observed in giving the rain gauge such a position as that nothing may obstruct the rain in its most oblique direction from entering it, and no sediment must be suffered to remain in it. The rain gauge must be kept remote from all elevated structures, to a distance at least equal to their height, and s:ill farther off where it can be conveniently done, and be not more than ten feet above the surface of the ground. In freezing weather, when the rain gauge cannot be used out of doors, it may be taken into a room, and instead of it a tin vessel should be procured for receiving the snow or sleet that may fall; this vessel must have its opening ex- actly equal to that of the rain gauge, and widen down to a sufficient depth, with a considerable slope. It should be placed where nothing can obstruct the descending snow from entering it, and where no drift snow may be blown into it. During a continued snow storm the snow may be occasionally pressed down into it. The contents of the vessel must at proper times be melted over a fire, and the water produced poured into the gauge to ascertain its con- tents, which must be entered in the gauge column of the register. Price, $2.50. Cylindrical Rain Gauge.—(Fig. 623, next page.)—This instrument is a cylindrical vessel, about four feet high, and three and a twelfth inches in diameter, mounted on a base resembling the segment of a cone ; the lower diameter of which is thirteen inches, the upper three and a twelfth inches, and the height eight inches. The base may be filled with sand, or other heavy material, to make the instrument steady; and the general form being that of an upright pedestal, it is a neat ornament for the garden or pleasure grounds. At the top of the cylinder is an open basin, cor- responding with the base, having an aperture one-twelfth of an inch in diameter. The depth of the rain is indicated by a graduated glass tube, communicating with the bottom of 144 BENJ. pike's, jr., descriptive cata Fig. 623 fllllllllllllKHIIIIIIIIIIIIHiiKKIIllliimiy tio:i i made. the cylinder. The water stands at the same height in the cylinder and glass tube, and being visi- ble in the latter, the height is read imme- diately on the scale ; and the cylinder and tube being construct- ed so that the sum of the areas of their sections is a given part, for instance a tenth, of the area of the funnel at its ori- fice, each inch of water in the tube is equivalent to the tenth of an inch of water entering the mouth of the funnel. A stop-cock is add- ed, by which the water is drawn off when the observa- It is usually made of tin, and well japanned. Price, $7.50. The same, with float within the cylinder and scale in the form of a rod, indicating the quantity by the rise of the rod and float. Pnce' $6-00- Lind's Wind Gauge.—{Fig. 624, as above.)—An instru- ment serving to determine the velocity and force of the wind. An apparatus which is simple and easy of construction, and which seems to be well adapted for measuring the force of the wind with a sufficient degree of accuracy, consists of two glass tubes, a b, c d, five or six inches in length, and about four-tenths of an inch in bore ; which are connected together like a siphon, by a small bent glass tube, a b, the bore of which is one-tenth of an inch in diameter. On the upper end of the leg, a b, there is a tube of latten brass, which is METEOROLOGICAL INSTRUMENTS. 145 kneed or bent perpendicularly outwards, and has its mouth open towards k ; on the other leg, c d, is a cover, with a round hole, g, in the upper part of it, two-tenths of an inch in diameter. This cover and the kneed tube are connected together by a slip of brass, cd, which strengthens the whole instrument, and serves to hold the scale, h i. The kneed tube and cover are fixed on with hard cement, or sealing- wax. To the same tube is soldered a piece of brass, e, with a round hole in it to receive the steel spindle, K L, and at /another such piece of brass is soldered to the brass hoop, g h, which surrounds both legs of the instrument. There is a small shoulder on the spindle at/, upon which the instru- ment rests, and a small nut, i, to prevent it from being blown off the spindle by the wind. The whole instrument is easily turned round upon the spindle by the wind, so as always to present the mouth of the kneed tube towards it. At the end of the spindle there is a screw, by which it may be screwed to the top of a post or stand ; it has also a hole at L, to admit of a small lever for screwing it into wood with greater facility. A thin plate of brass, k, is soldered on the kneed tube, about half an inch above the round hole G, so as to prevent rain from falling into it. This instrument serves to ascertain the force of the wind, by filling the tube half full of water, and pushing the scale a little up or down, till 0 upon the scale, when the instru- ment is held perpendicularly, be on a line with the surface of the water, in both legs of the wind-gauge. The instru- ment being thus adjusted, hold it up perpendicularly, and turning the mouth of the kneed tube towards the wind, ob- serve how much the water is depressed hy it in one leg, and how much it is raised in the other. The sum of the two is the height of a column of water, which the wind is capable of sustaining at that time ; and every body that is opposed to that wind, will be pressed upon by a force equal to the weight of a column of water, having its base equal to the surface that is opposed, and its height equal to the altitude of the column of water sustained by the wind in the wind- gauge. Hence the force of the wind upon any body, where the surface opposed to it is known, may be easily found ; and ready comparison may be made betwixt the strength of one gale of wind and that of another, by knowing the heights of the columns of water which the different winds were ca- VOL. II, .—13 146 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. pable of sustaining. The heights of the column in each leg will be equal, provided that the legs are of equal bores; but unequal if their bores are unequal. For suppose the legs equal, and the column of water sustained by the wind to be three inches, the water in the leg which the wind blows into will be depressed one and a half inch below 0, and raised as much in the other leg. But if the bore of the leg which the wind blows into be double that of the other, the water will be depressed only one inch, whilst it is raised twice as much, or two inches, in the other, and vice versa. For obtaining in this case the true height, Dr. Lind has subjoined the requisite formulae. The use of the small tube of communication, a b is, to check the undulation of the water, so that the height of it may be read off from the scale with ease and certainty; and also to prevent the water from being thrown up to a much greater or less alti- tude than the true height of the column which the wind is able at that time to sustain. The author has calculated a table, by means of which, having the height of the column of water sustained in the wind-gauge, the force of the wind upon a foot square may be determined. Force of the Wind Height of Water on one foot square Common designations of such in the Gauge. in pounds Avoir-dupois. Winds. Inches. 6 31.750 Hurricane. 5 26.041 Very great storm. 4 20.833 Great storm. 3 15.625 Storm. 2 10.416 Very high wind. 1 5.208 High wind. 0.5 2.604 Brisk gale. 0.1 0.521 Fresh breeze. 0.05 0.260 Pleasant wind. 0.025 0.030 A gentle wind. When the height of the water is not exactly mentioned in the table, then that height may be separated into such parts as are mentioned in the table, and the sum of the forces an- swering to such parts will be the force of the wind corre- spondent to the height in question : thus, if the height of the water be 4.6 inches, then this height is equal to 4+0.5+0.1, which parts are all on the table; therefore, METEOROLOGICAL INSTRUMENTS. 147 Inches. Pounds. 4 - 20.833 0.5 - 2.604 0.1 - 0.521 The sum is 23.958, which expresses the force of the wind when the height of the water in the sraup-e is 4.6 inches. Any alteration that can usually take place in the tempe- rature of the water, makes no sensible difference in this in- strument. In frosty weather this gauge cannot be used with common water. At that time some other liquor must be used, which is not subject to freeze; and, upon the whole, a saturated solution of common salt in water is the most eligible; but in that case (since the specific gravity of a saturated solution of salt is to that of pure water, as 1.244 to 1) the forces which are stated in the preceding table must be multiplied by 1.244. Thus, if in the preceding example the saturated solution of salt had been used instead of water only, the force of the wind on a square foot would have been 29.8 lbs. When salt-water is used, the force of the wind, which is stated in the table, must be increased in the proportion of the specific gravity of salt-water to that of common wa- ter; thus, using the preceding example, we must say, as 1 : 1.244 :: 23.958 to a fourth proportional, which must be found by multiplying the second term by the third, and then dividing the product by the first term; but, the first term being unity, we need only multiply 23.958 by 1,244. Price, $6.00 to 88.00. Dr. Cumming's Statical Fig. 625 Thermometer. —(Fig. 625.Y— E»'"l!'.......■"!'■ ","'"'~r71y~T7~^~Tr"3 An instrument intended as a P» je " mode of opening windows and jffgjt. ventilators in apartments, by C-^dA the variations in temperature ^Ip^ of the included air. | B A is a tube and ball, either of fir glass or iron, the ball being IH capable of holding four or five gj§: pints of air, and the tube, b, |j| c about twenty-five inches long. -|j§-»- A portion of the tube is filled ^—' 148 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. with mercury, and in this state is inverted and the end plunged in a jar of the same fluid ; to the top of the ball is attached a string, which, after passing over the pulleys, d and e, is finally fastened to the window, f. When the heat of the apartment rarities the air in the ball, the mercury is driven out, and the ball and tube being thereby lightened, rise and suffer the window to swing itself ooen An increase of cold will produce the contrary effect. r ' Price, $25.00. OPTICAL INSTRUMENTS. SPECTACLES. When two lenses are mounted in a frame to fix before the eyes, they are denominated spectacles ; the lenses are employed to render the objects before the wearer more dis- tinct. The eye, which consists of a convex lens, called the crystalline lens, refracts the light proceeding from the object placed before it in the same manner as a convex glass; the image of the object is formed at the focus of the lens, where it is received on a screen at the back of the eye; this screen, called the retina, is an expansion of the optic nerve, which conveys the sensation of vision to the mind. As the crystalline lens of the eye will only produce distinct vision when the focus is thrown on the retina, it is obvious that should any defect occur with respect to that organ, indis- tinct and imperfect vision will arise. Thus, if the lens of the eye is not of a proper convexity to bring the image on the screen, an indistinctness must ensue. This is the case when the lens, through age, has become flattened ; the image will then be thrown beyond the retina, and thus convey an imperfect representation of the object to the mind. To obviate this defect, we must make the rays pass through a glass of sufficient convexity to assist the eye, and enable it to form the image at the required place, which is in this instance done by shortening the focal distance of the crystal- line lens of the eye. If, on the contrary, the eye should be too convex, or short-sighted, as is often the case with young persons, then the image will not be formed at a sufficient distance from the lens of the eye to reach the retina, and thus imperfect vision of distant objects is produced. To remedy this defect concave lenses must be resorted to, in 13* 150 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. order to diverge the ravs before they enter the eye, and thus lengthen the focus'of the crystalline lens to form an image on the retina. When the eyes are not directed near the centre of the spectacle-glasses, the obliquity of their surface to the rays will be increased, so as to occasion a confused appearance of the object. A great portion of this confusion is removed in the spectacles now usually made, when compared with those formerly employed, whose size, being very large, augmented the imperfection; for it may be observed that when objects are seen through spectacle- glasses, no more of the glass is employed at one view than a portion equal to the size of the pupil of the eye; this on an average may be reckoned at the eighth of an inch in diameter. Thus, we see how small a portion is used for the purposes of vision ; but as it would be tedious to require the eye always to look through a small aperture, the glasses are left of a sufficient size to admit of a moderate degree of motion ; and as we require a greater latitude horizontally than vertically, their figure is made of an oval, oblong, or octagon form. The mountings are usually of gold, silver, and fine steel; these last rapidly superseding the others owing to their extreme lightness and elasticity, though many are sold which are mere imitations of the genuine article, having little or no elasticity; the bows are formed to slide, to turn, and with single branches, which last are convenient for ladies—not disturbing the hair; and for gentlemen requiring expedition in placing them on. Tortoise-shell mounted spec- tacles are also worn for extreme lightness, and by those objecting to metal frames; are pleasant to wear, but liable to be easily broken. In the selection of spectacle-glasses great care should be used in examining thern, and the first point of importance is the goodness of the material of which they are formed; this should be free from all veins or small bubbles, for if one of these occur in the portion through which we look, it will greatly impair the eyes. The next circumstance is that the figure of their surfaces should be perfectly spherical, for if they are curved more in one direction than in another they will injure the sight. The polish should be clean, and free from flare, which too often arises from the manner in which they are usually polished on heterogeneous surfaces, pro- ducing what is technically termed a curdled glass. OPTICAL INSTRUMENTS. 151 Periscopic Glasses.—(Fig. 626.)—Dr. Wollaston, in order to allow the eyes a consider- able latitude without fatigue, invented a peculiar form of glasses, called by him peri- scopic, from two Greek words signifying seeing about; their form is that of a meniscus with the concave side always turned towards the eye. When they are intended for long-sighted persons, or old age, the anterior surface, or that next the object, is formed spheri- cally convex, with a curve deeper than the concave, so as both to gain the required power, and compensate for the divergency occasioned by the concave side; this form is shown at a, in the above cut. The periscopic form em- ployed for correcting the defect of a short or near-sight is shown in section at b, having its anterior surface convex, as in the former case ; but here the concavity on its posterior side is increased to procure the required divergency, and compensate for the convex side. Pebbles are made from blocks of rock crystal, usually brought from the Brazils; are cut into slices by the lapidary and ground to convex, concave, or periscopic forms by the optician for spectacles. They have the advantage of being more transparent than glass, much harder, do not scratch, take a higher polish, and consequently transmit more light; also are cooler to the eyes. The price of the best convex pebbles is usually $2.25, and for concave $3.25, or where they are purchased with the frames $1.75 extra, for convex, and $2.50 for concave. 152 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Spectacles.—Oblong-eye Turnpin Bows.—(Fig. 627.) Oval-eye Turnpin Bows.—(Fig. 628.) Oblong-eye Single Temples for Lul'a..—(Fig. 629.) Price, in silver, - . $2.00 and § 2 25 " in gold, $7.00, $8.00, $9.00, and $10.00. OPTICAL INSTRUMENTS. 153 Spectacles.— Octagon-eye Sliding Bows -(Fig. 630.) Octagon-eye Turnpin Bows.—(Fig. 631.) Octagon-eye Single Bows, for Ladies.— (Fig. 632.) Price, silver, $2.00 and $2.25. gold, $8.00, $10.00, and $14.00. 1M BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Spectacles.-Fine Elastic Steel Frames, Octagon Eye Turn- ■ n tv «m\ Price $2.50; extra fine, &3. jnn Bows.-(Fig. 633.) Puce, ^.^ ^ ^ ^ Fine Elastic Steel Frames, Oblong Eye with Turnpin Bows fF. fiS4 x Price, $2.50 ; extra fine, $3 ; ""^'S- bd4'> .. ordinarv, $1 to $1.50. Fine Elastic Steel Frames, Oblong Eye, with Single Bows, for Ladies.—(Fig. 635.) Price, $2 ; extra fine, $2.50. " ordinary, $1 to $1.50. 9 OPTICAL INSTRUMENTS. 155 Oval Eye Tortoise-Shell Spectacles, with Single Bows.— (Fig. 636.)—Tortoise-shell mounted spectacles are worn for extreme lightness, and are pleasant to wear, but liable to be easily broken; they are sometimes mounted with silver, or gold bows, having single or double branches. Price, single side, $2.00; turnpin side, $3.00. with silver bows, $3.00 and $3.50. Spectacles for Reading and Public Speaking.— (Fig. 637.)— Spectacles adapted for read- ing and public speaking, having the top of the rim holding the glass flat, and being worn before the eyes in such a man- ner as to see through the glass in reading, and over the frame in speaking, and are particularly use- ful to clergymen and other public speakers, requiring the use of spec- tacles ; they are mounted in silver, fine steel, and gold. Price, in " silver, $2.80. " in fine steel, $2.50. and $3.00. " ordi- nary, $1.50. "gold, $10.00. 156 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Fig. 63a F* *»■ Large Double Eye Spectacles, or Eye Protectors.—(Fig. 638.)—Large double eye spectacles with shaded glasses, are particularly useful to persons having weak eyes, and for riding, driving, &c, in the dust, wind, &c.; the glasses are large and shaded, blue, grey, green, and neutral tint; the OPTICAL INSTRUMENTS. 157 best mounting for them being fine steel, being the lightest, and attaching firmly to the head. Price, of best quality, - - $5.00. 2d commoner, $4.50. $2.50. " with ordinary size glasses, $1.50. Spectacle Cases.—(Fig. 639.)—The cut in the previous page represents the usual style of the morocco spectacle case. They are also made soft, with one or both ends open, and occupying but little space in the pocket, but not protecting the spectacles, as the one represented in the cut. They are made of a variety of colors, but most usually red and dark blue. Price, 12icts. Single Eye Glasses.—Eye glasses are frequently used instead of spectacles, being less formal and more convenient for occasional purposes, as in reading a letter, viewing any object for a moment, either near or distant as the case may require. They are mounted in a variety of setting, black horn, tortoise-shell, fine steel, silver, and gold (those* in tortoise-shell being the most used), and are worn sus- pended from a guard around the neck. Round Shell Eye-Glass.—(Fig. 640.) Fig. 610. Price, round shell eye-glass, $1.00. " black horn eye-glass, 63 cts. vol. n.—14 158 BENJ. PIKE'S. JR., DESCRIPTIVE CATALOGUE. Fig. 641. Square Shell Eye-Glass. (Fig. 641.) I Price, square shell eye-glass, $1. " square black horn, 75 cts. Fine Steel Eye-Glass.—(Fig. 6 12.) fig 612. Price, $1 to $1.25. Gold-mounted Eye-Glass.—(Fig. 643.) Fig. 64i Price, $3.00. OPTICAL INSTRUMENTS. Gold-mounted Eye-Glasses.—(Fig. 641.) Fig. 611. 159 Price, $5. each. Gold-mounted Reader—(Fig. 045)—which may be held between the eye and object, the lens being larger than the eye-glass Fig. 645. Price. $4.50 and $5.00. JR., DESCRIPTIVE CATALOGUE. Double E'/e Glasses.—"Double eye glasses are rapidly super- seding the ise of the single eye glass; persons seeing more and better with two eyes than with one. Single eye glasses have a tendency to weaken one eye, as the wearer will invariably apply the glass to one eye more than the other, and thereby induce a difference in them. The wearer of a dou- ble eye glass will also see better for a longer time, and with more pleasure to himself, than with a single eye glass. They are mounted in black horn, tortoise- shell, fine blued steel, silver, and gold ; most of which may be fixed on the nose by slightly pressing the glasses nearer to each other, when the wearer may have the advantage of using both hands if required. Tortoise Shell Double Eye Glass.—(Fig. 646.) Price, in black horn, $1.00. and $1.25. " tortoise-shell, $1.75. <( << << with spring, $2.25. to - - $3.00. OPTICAL INSTRUMENTS. 161 Fine Steel Double Eye Glass.—{Fig. 647.) Fig. 617. 999999999999999� 162 BENJ. PIKE'.-?, JR., DESCRIPTIVE CATALOOUE. Double Eye Glass in Gold.—(Fig. 648, previous page.)— These eye glasses are made in a variety of elegant forms, some having springs, and by touching the head of a small pin in the handle, the spring is loosened and the glass opens; others are formed for supporting on the nose by a slight pressure. This description of eye glass is not made of solid gold, but of a thickness sufficient for the roughest use. Price, $5.00, $6.00, $7.00, and $10.00. Fig. 649 OPTICAL INSTRUMENTS. 163 Horn Mounted Readers—(Fig. 650)—Consists of a large convex glass set in a horn frame, folding into a case of the same material, and are used for reading, &c, held in the hand, midway between the object and the eye, but a slight movement of the hand being made. The drawing represents the usual size of the article. Price, $2.00 ; smaller size, $1.50 and $1.00. Fig. 650. 164 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. Silver and Pearl Mounted Reader.—(Fig. 651.)—This is a substantial and neat made silver frame, containing a large convex lens mounted to a case of tortoise-shell, or pearl, by ornamental plates of silver, and turning on a pivot into the case. The cut represents the full sized reader. Price, $10.00 ; smaller size, £8.00 and $6.00. i ig. 652. Videoscope.—(Fig. 652.)—An a£ optical instrument for drawing reading, sewing, or any particular work, having a clamp to screw to a table, with a joint and sliding tube for adjustment (the tube may be made fast by screwing the nurled nut on it), so that the lens may be fixed in a convenient position, either leaning over the table or projecting from it. Price, $5.50. OPTICAL INSTRU Goggles (Fig. 653) are used by persons having weak eyes, in riding, driving, or walking, as a protection against the wind, dust, light of the sun, or large surfaces of water, snow, &c. They consist of glasses, white or shaded, usually with plain sur- faces, set in silver plated, or black horn rims, and mounted in leather at a proper distance to be supported before the eyes by strings passing round the head. Price, 75 cts. and $1.00. Wire Gauze Goggles, or Eye Protectors.—These are an excel- lent protector for the eyes, and are a great improvement on the ordinary goggles, preventing the heating of the eye by the con- tact of the leather mounting in the old kind, and allowing the evaporation from the surface of the eye to pass off unobstructed, and as a shade to the eye, will be found serviceable and agree- able. They consist of an oval shaped frame of wire, formed to fit closely around the eye, hav- ing caps of fine iron wire gauze, covered with a dull varnish, of sufficient size and convexity to allow the eye-lashes to move freely and unobstructed therein, and supported by strings pass- ing round the head. The effect on the eye being about the same as having a thick veil before it, ■ L66 benj. pike's, jr., descriptive catalogue. taking off the glare of light. but allowing objects to be seen with distinctness, also keeping of all dust and wind that would injure the eye, even in a weak state, with- out destroying that ventila- tion necessary for the health of the eye. They are also particularly serviceable in riding in rail-road cars ; the sparks from the cinders fre- quently occasioning serious accidents by their falling in the eye, which the use of these will prevent. Price, $1.00. (Fig. 654.)—They are also set with glasses in the centre of the cup, as represented in the cut, which may be white, or shaded blue, grey, or green ; either convex, or con- cave, but usually with plane surfaces, neither magnifying nor diminishing. Price, $1.00 and $1.25. OPTICAL INSTRUMENTS. 167 Goggles for Squinting.—(Fig. 655.)—These goggles are instru- ments used for curing squinting, or that distortion of the eyes which oc- casions this disorder; they are short conical cups of ivory, horn, or hard wood stained black. Through the centre of each of these cups is a small circular hole, about the size of the pupil of the eye, for the transmission of the rays of light. They are mounted in a leather frame, and worn continually in the day time, till the muscles are brought to act regularly and uni- formly, so as to direct the pupil straight forwards; and by these means the cure will be sooner or later effected. Price, 88 cts. Fig. 656 is an improved mount- ing for the above, in wire frames, preventing the heating of the eye by the leath- er mounting. Price, §1.50. 168 BENJ. pike's, jr., descriptive catalogue. Fig. 657 Fig. 638. Magnifier. The common magnifying glass or simplest kind of microscope is nothing but a converging lens of very short focus. This in- strument enables us to see objects which could not possibly be seen by the unassisted sight. The bota- nist detects by means of it the delicate organs of plants, and workmen in every department of the arts use it for minute adjustments and operations. (Figs. 657, 658, and 659.)—These are variously mounted, most usually having a rim of black horn, turning on a pivot into a box of the same material, and having a slight pro- jection on one side of the rim, to open it conveniently. They are made of three sizes as represented in the cuts Price, 75 cts., 50 cts., and 44 cts. OPTICAL instruments. Fig. 660. 169 Botanical Lenses, or Magnifiers.—The haste with which botanists, Sec, frequently have occasion to view objects, renders a pocket magnifier very useful. The most conve- nient of any constructed are those represented in Figs. 660, 661, and 602, which are drawn of the medium size, there being a size smaller and one larger ; this form of mounting vol. n.—15 170 benj. pike's, jr., descriptive catalogue. is much preferable to those with round cases, being more convenient to hold. They are made with one, two, and three lenses. Those with three frames are usually set with one, one and a half, and two inch focus lenses; they all turn over_e.ich other and shut in the case, and are turned out at pleasure. The three lenses singly, afford three magnifying powers, and by combining two and two, we make three more, and all three together, one more, making seven different degrees of magnifying with the three glasses only. Price, single lens magnifier, - - $0.62. " larger size, $0.75. double " - - - $1.00. " larger size, $1.12. " treble lens magnifier, - $1.38. larger size, $1.50. Fig. 663. Fig. 664. Watchmaker's Magnifier.—(Fig 663.)—The watch magnifier con sists of a convex lens of about two inches focus, set in a deep horn case, the larger end of which is of such a size and form, as to be held between the eyebrow and bone of the cheek without incon- venience. The cut represents the size of the article. Price, 38 cts. Engraver's Magnifier. —(Fig. 664.)—The en- graver's magnifier consists of a convex lens, about one and a half inches in diameter and two inches focus, set in a deep horn case, which is usually sup- ported over the work to be engraved by a suitable stand; the eye viewing the work through the lens while engravinar. Price, To cts. OPTICAL instruments. 171 Engraver's Magnifier (Fig. 005), larger size, in cocoa wood frame. ....... Price, $1.00 Extra large, $1.75. I ig. 666. Engraver's Double Lens Magnifier. —(Fig. 666.)—The engraver's dou- ble lens magnifier consists of two plano-convex, or periscopic lenses, mounted with their convex sides in- ward, in a brass frame, the cells unscrewing to clean the glasses oc- casionally. This construction of magnifier is preferable for persons in constant use of these glasses, and desirous of straining their eyes as little as possible in the use thereof, there being less spherical aberration in two lenses thus arranged than in others. Price, $1.50 and $1.75. Hand Magnifiers.—-(Fig. 667.)— This consists of a convex lens, mount- ed in a metal frame, and attached to a long handle, by which it may be Fig. 657. 172 BENJ. pike's, jr., descriptive catalogue. held for viewing any object, and is well suited for viewing daguerreotypes. Price, 75 cts. Fig. 668. Double Lens Hand Microscope, or Doublet. —(Fig. 668.)—This is the most powerful in- strument, for the price that it is sold for, that is to be obtained. It consists of two plano-convex lenses, with the plane surfaces outwards, mounted in cells and screwed in a frame having an ivory handle ; where a person has skill to use a great power, this is a desirable instrument. The cut represents the size of the article. Price, $1.00. Fig. 669. The above cut (Fig. 669) represents the same article of a larger size, not having so great a magnifying power, but a greater field of vision ; it may be used with one lens only, by unscrewing the other. Price, in brass mounting, $0.75. " in German silver, $1.00. Fig. 670. Stanhope Lens.—(Fig. 670.)— This simple but very powerful lens is the invention of Lord Stanhope ; both ends are ground convex, the one next the eye rather more so than the other. It has many advantages over the common lens : for instance, the difficulty of holding the hand steady to the focus, and the loss of light and field attendant on viewing with a high magnifying power, are here obviated ; for, the length of the cylinder being the exact focus, the object has only to be placed upon the end that is ground less convex, or to be brought in contact with it, when the optical instruments. 173 advantage of great magnifying power will be obtained, with a field nearly equal to many of the compound microscopes. The portability of this instrument, its low price, and the facility with which it can be used, must recommend it strongly to all who use microscopic lenses. With it may be viewed the animalcules in water, mites in cheese, eels in paste and vinegar, the perspiration, human hair, farina, and leaves of flowers, the hairs of animals, the down of moths, &c. ; and if a single drop of the crystallization of salts be spread lightly over the end of the lens, and viewed without delay, the formation of the crystal will be beautifully appa- rent. Price, $'2.00. Linen and Cloth Prover.—(Figs. 671 and 672.)—This in- strument for ascertaining the fineness of linens, muslins, bolting cloths, &c.; by ascertaining the number of threads in a given space under a powerful magnifying glass, consists of a lens mounted in a brass frame, about one inch over a square hole that is exactly half, or quarter of an inch square, and situated in the focus of the lens. The hole is placed on the linen, or fabric to be examined, and held in a position to receive a strong light, when it will appear, on viewing through the lens, magnified to such an extent that the number of threads in the space may readily be counted, and the fineness thereby accurately ascertained. This instru- ment will answer the purpose of magnifying small objects, placed on the top of the plate, equally well. They are inclosed in small round boxes of wood or brass. Price, in wood box, - - 63 cts. " in brass " - - 75 cts. " " " extra finish, 88 cts. 15* Fig. 671. 174 benj. pike's, jr., descriptive catalogue. c having on one end aground glass. When the A)[ lens representing the eye is held towards any lij, object, the inverted image may be seen on the II ground glass; and by placing a concave or convex lens in front of the lens in the instru- ment, the effect of long and near sighted vision is beautifully seen. Price, $2.50. Fig. 696. Instrument to show the nature of Vision.—(Fig. 696.)— This instrument is mounted on a neat mahogany base thirteen inches long, on which is supported from a short pillar, a glass globe, four inches in diameter, having an opening on two sides, about two inches wide: in one of these apertures are represented the outer lenses of the eye; near the other end of the base is an object, about six inches high, which is movable for about two inches, being fixed on one side. To the object are attached nine silken strings, of different colors, representing rays of light, and passing through holes in the lenses of the eye, are united to an in- verted image of the object, at the place of the retina. The whole arrangement of strings attached to the erect object, and crossing at the lenses of the eye and uniting the inverted vol. n.—16 182 BENJ. pike's, jr., descriptive catalogue. Fig. 697. object, may be moved beyond the retina, as in the long- sighted eve; or within the retina, as in the near-sighted eye ; or when placed at the retina, perfect vision; thus ex- plaining, in a clear manner, those positions of the image in regard to the retina. P«ce, $6.00. Muscles of the Eye.— (Fig. 697.)—This in- strument represents the globe of the eye revolv- ing in its socket, and consists of a ball, about four inches in diame- ter, having attached to it stout pieces of tape, representing its four straight and two ob- lique muscles, having their proper names attached; also showing the beautiful arrangement of the oblique muscle near the nose, giving a correct idea of that Avonderful ar- rangement in the human frame. The ball of the eye may be moA-ed in all directions. The Avhole is mounted on a neat mahogany stand, about 12 inches long. Price, .... $2.50. or the whole set, - $13.00. first, third, and fourth, $11.00. The Prism. — (Fig. 698.)—A triangular piece of glass employed to separate a ray of light into its constituent parts or colors by re- fraction. The prism is the instru- ment by which the most remarkable phenomena of light and colors are exhibited. To use the prism, let a room be darkened, and the sun permitted to shine into it through a small hole in the window shutter, it will give a circular white spot; but let it be made to fall on the glass prism, then will the sun's rays in passing through the prism suffer different degrees of refraction, and by that means be parted into different rays, which beino- received upon a sheet of white paper will exhibit the follow* OPTICAL INSTRUMENTS. 183 ing colors, viz. red, orange, yellow, green, blue, indigo, and violet; and if the whole spectrum or image be divided into 360 equal parts, the red will occupy 45 of them, the orange 27, the yellow 48, the green 60, the blue 60, the indigo 40, and the violet 80. Place the prism horizontally near the eye, Avith one of its faces upwards so as to receive the light that enters on the opposite face, and the following remarkable phenomena will be observed ; the light will have undergone considerable deviation, so that all objects will appear elevated towards the summit of the prism, and will appear colored at their edges with all the colors of the rainbow. If the face of the prism is downward the objects will be displaced down- ward. If the prism be placed vertically, the deviation will take place to the right or left as the position is altered. Price, 38 cts.; $1.00 ; $1.50 ; $2.00 and $3.00. " mounted (Fig. 698), $2.00 to $5.00. Compound Prisms.—Prisms are sometimes formed of different kinds of glass, as crown, flint, and plate glass, for showino- their different refractive powers. ° Price, $3.00. Instrument for the Recomposition ^Fig.699. of Light—(Fig. 699.)—This instru- ment for the recomposition of light, sometimes called a color blender, is conveniently formed in the shape of a large top, about five and a half inches in diameter, which, by means of a string and handle, may be rapidly spun around for a considerable time. On the sur- face of the top there is accurately described the proportion of the different colors, which are engraved on a plate, near the centre, while the exterior is filled with colored papers, each color of nearly the color of the spectrum, and occupy- ing the same proportion, viz. violet 80, indigo 40, blue 60, green 60, yellow 48, orange 27, red 45 ; the Avhole is var- nished to protect it from injury. As the rays of the sun may be separated into these seven* primitive colors, so, by their mixture in due proportions, nay white be produced. White, therefore, is the mixture 184 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. of all the colors, as black is the want or deprivation of color; which may be proved by this instrument Though seven different colors are distinguishable in the prismatfc spectrum, yet, upon examining the matter w, h more accuracy, we snail see that there are in fact, only three original colors-red, blue, and yellow, for the orange beina situated between the red and yellow, is only the mix- ture°of these two ; the green, in like manner, arises from blending the blue and yellow, and the violet results from the blue and red. Price, $1.00. Glass Box for Experiments on Refraction.—(Fig. 700.)— This consists of a metallic box, open at top, from 8 to 14 inches long, and from 5 to 9 inches wide, having true plate- glass sides. Each end has a circular aperture, about 2 inches wide, the one having a meniscus glass with the convex sur- face outwards, and the other having one with the concave surface outwards. The box is made water-tight, and is usu- ally supported on a neat base, and furnished with a cock, for the more easily emptying it of water. Fig. 700. To use it, cause a ray, or pencil of light, from a hole in the window, to fall on the bottom of the box, where you may make a mark; then fill the box with water, without moving it out of its plaee, and you will see that the pencil of light, instead of falling on the mark, as before, will be refracted, or bent out of its former course. A few drops of milk added to the Avater will make the course of the ray of "light more distinct. If a small mirror be laid on the bottom of the box when filled with water, the light will be reflected from it, and will be observed to suffer the same refraction as OPTICAL INSTRUMENTS. 185 in coming in, only in a different direction. Place the box so that a pencil of light falls directly on the convex glass, at the end; as soon as water is poured in the box, the rays converge and meet in a point; cause the pencil of light to fall on the concave glass, and the rays diverge, and the pencil of light is enlarged. Many other experiments illus- trating refraction, and the passage of light through lenses, may be illustrated in a beautiful manner by this instrument. Price, $4.00 and $5.50. The Optical Diagonal Ma- Fis- ™L chine, Print Glass, or Cosmo- ramma (Fig. 701), consists of a convex lens from four to six inches in diameter, mounted in a square frame, and supported by an ornamental framework resting on a round pedestal, in the column of which is a slide, and a screw to fix it any height required to vieAvthe print with the best effect; behind the lens is a frame, with a mirror considerably larger than the lens, which is jointed at the top, and may be supported at a proper angle by a wire for the purpose. The prints are laid on the table, and viewed in the mirror through the lens, producing a very deceptive appearance, and in imagination bringing the reality before you. The frame is of polished Avood, and may be token apart by unscrewing for convenient transportation. This instrument, used for magnifying prints, is neat in its appearance and useful in its application ; pictures are very interesting to children, and give them a very just idea of the relative size and distance of objects ; they also teach them accuracy of sight, engage their imagination, and fix their attention, promoting many inquiries, Avhich, if judiciously ansAvered, will store their minds with useful information. Good perspective views designed for this instrument, handsomely colored, fourteen inches by tAventy-two in size, embracing views of many of the most celebrated public buildings of the principal cities in Europe, interiors of public 16* L86 benj. pike's, jr., descriptive catalogue. buildings in Rome. London, &c, views of shipping, land- scape Views, &c, to the number of one hundred and upwards, may be obtained with the instrument, for the low price of eight cents each, which is not one half the price usually charged. Price diagonal print glass with 4 inch lens, $2.75. « ' °« « << "5 " " $3.25. " 6 '• " $3.75. " prints, 14 by 22 inch, per dozen, $1.00. " " " hundred, $8.00. The Portable Camera Obscura.—(Fig. 702.)—This con- sists of a box usually about twelve inches long, having one end attached to a movable slide, which may be drawn out a few inches, in which is fixed a convex lens, of a suitable focus ; Avithin the box is placed diagonally a mirror, so as to reflect the object on a ground glass, occupying nearly half of the top of the box, and over which is hinged a screen or shutter having closed sides, moving Avithin the sides of the box to exclude the external light; on the rough glass external objects are beautifully represented, affording a pleasing amusement to young persons, as representing a moving panorama of animated nature. Fig. 702. Directions for Use.—Place on the ground glass a piece of good tracing paper, and present the instrument to the object to be copied, which should be strongly illuminated. The camera should be placed level. Draw the slide till the ob- ject is reflected on the paper, and if the lines are followed with a pencil, a correct copy of the vieAv will be obtained. If a portrait be desired, the person should be placed in the OPTICAL INSTRUMENTS. 187 proper position, in a strong light, and the lines traced as above, when a correct likeness may be obtained by persons unacquainted with drawing. Price, 12 inches long, $3.50. " 18 " $6.00. A simple camera obscura may be constructed in the fol- lowing manner : fix a convex lens, from one to three inches diameter, in the hole of a window shutter, and if no light enters the room but through the glass, the pictures of all objects on the outside may be seen in an inverted position on a sheet of white paper placed at the focus of the glass, or at such a distance from it as they may be represented clear and distinct. Price, 25 cts. to 75 cts. Draughtsman's Came- ra Obscura and Cosmo- rama. — (Fig. 703.) — This convenient arrangre- mentof the camera when set up is twenty-one inches high, the sides are hinged, and Avhen not in use, may, together with the other parts, be folded down into the case; the usual size be- ing eighteen inches long, fourteen inches wide, and seven and a half inches deep; the larger size being twenty-four inches long, and of proportional dimensions. The lens and mirror, the latter inclined at an angle of 45 degrees, are contained in a box on the top of the case, which may be turned around and directed to any part of the horizon ; also havino- a slid- ing motion for adjusting the focus. The object is received by the lens, and reflected by the mirror to a sheet of white paper placed on the bottom of the box. One side of the box is cut to admit the head and arms of the person avIio desires to trace with a pencil the objects delineated. This instrument also forms an excellent cosmorama, by placino- 188 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. prints on the bottom of the box, and viewing them reflected by the mirror through the lens. Price, $8.00; extra large size, $12.00. Fig. 704. Fig. 705. Daguerreotype Camera.—The camera obscura, used for taking daguerreotype pictures (Fig. 704), consists of a ma- hoo-any box, on the front of which is fixed a brass sliding tube, A, containing two achromatic lenses. The image is received on a piece of ground glass, fitted in a frame, B, which slides in a groove in the back of the camera, and the focus is adjusted to the greatest nicety by a fine rack-work movement in the brass tube containing the lenses. The frame, B, may be withdrawn, and an- other frame, C (represented in Fig. 705), introduced, consisting /£lo{ a box, made to receive thin Avooden frames, which are grooved around and adapted for receiving the various sized daguerreotype plates to be used. This frame is furnished with a sliding shutter, D, in front of the plate to prevent the ac- cess of light to the plate till placed in the camera. E is a hinged flap Avith spring to keep the frame and plate in their proper position. OPTICAL INSTRUMENTS. 189 Daguerreotype pictures are taken on copper plates, covered with a coating of silver of a sufficient thickness to allow of its being finely polished. The method of proceed- ing consists of five distinct operations, viz. 1. Cleaning the silvered plate. 2. Rendering its surface sensitive to light by exposing it to the vapor of iodine, &c. 3. Exposing the prepared sensitive plate to the focus of the camera. 4. Brino-ing out the picture by exposing it to the vapor of mer- cury? 5. Setting the picture by removing the sensitive sur- face of the plate which has not been acted upon by the lio-ht; and lastly, they are sometimes colored, Avhich is done by hand in a manner similar to painting. Price, of camera with mahogany or rose- wood box, - - - $25.00. " common stand, - - - $ 4.00. " two coating boxes, for coating the plate Avith iodine and quick stuff, the pair, $ 4.50. " cast iron mercury bath, - - $ 1.25. " thermometer for mercury bath, $ 0.50. " spirit lamp, - - 25 cts. to $ 1.00. " plate vice, for holding the plate while cleaning, $ 1.75. " buffing stick, for polishing the plates, $ 0.25. " head rest, with arrangements for at- taching to a chair, - - $ 3.00. " box of colors and brushes, - $ 3.00. " plates, medium size, 2f by 3 a inches, per dozen, - - - $ 3.00. " plates, quarter size, 3£ by 4£ inches, per dozen, - - - $ 4.50. Camera Lucida.— (Fig. 706, next page.)—By means of this instrument objects are represented on a sheet of paper, so that an accurate draAving may be made, even by those little accustomed to the pencil. In sketching from nature it is of the greatest use to the artist; an indifferent draughtsman may make an accurate drawing of the view before him. Portraits may be correctly taken the size of life, or in any less proportion. Paintings, prints, maps, drawings of machinery, instruments, furniture, &c, may be drawn in true perspective to any required scale. PIKE'S, JR., DESCRIPTIVE CATALOG Fig. 706. To use, fix the instrument to the table by the screw, with the stem in- clined. Place a sheet of paper under the prism, which must be turned, so that the face may be exactly oppo- site the object to be drawn ; by looking through the eye-hole downward on the pa- per a picture of the object will be seen. The proper position of the eye-hole is of the first importance in the use of the instrument; if the aperture is too far OA'er the prism, the pencil will be indis- tinct, and if not far enough the object can- not be seen sufficiently clear; a little practice will make this perfectly easy. In first attempting to use this instrument many persons lose sight of the pencil, merely by the motion of the bead in breathing, which they are not aware of. The longer the stem is drawn out, the larger the object will appear, and the view less extended. If the object to be drawn is two feet from the prism, and the paper one foot, the copy will be half the size of the original; if the object is one foot from the prism and the paper two feet, the copy will be twice the size ; and so in proportion for any intermediate distance. Price, $8.00 to $12.00. Graphic Mirror.—(Fig. 707, next page.)—An instrument for draAving objects in true perspective, and for copying, reducing, or enlarging other drawings. The upper part of the instrument consists of a triangular box, having a fixed reflecting mirror or looking-glass within it, and a transparent OPTICAL INSTRUMENTS. 191 plate of glass in the front, and which is ca- pable of adjustment. The rays from the ob- ject pass through the glass to the reflector, and upwards to the eye, Avhich sees them by looking through the small hole at the top. The form or ge- neral arrangement of all these instruments is similar, and easily un- derstood from the cut. The management of the instrument is best given in the inventor's own words, especially as they are applicable to all similar contri- vances. The instru- ment being fixed by the clamp and screw to the table and paper on which the drawing is to be made, look through the eye-hole having the front of the case Avhich contains the glasses opposite the object to be co- pied, adjusting it by means of the joints, and getting the first line perpendicular, the Avhole of the tracing will prove to be in true perspective. If objects can be seen distinctly on the upper part of the paper, and not on the lower, incline the part of the case re- flected downAvards by the joints, until the reflected image is on the part of the paper required. Many persons, upon first attempting to use the instrument, occasionally lose sight of their object or pencil by an unintentional motion of the eye ; to avoid which, contract the eye-hole by means of the eye- piece which covers it. 03930029 192 BENJ. pike's, jr., descriptive catalogue. The greater the distance from the object, and the higher the case containing the glasses is from the drawing paper the larger the image will be represented, which is obtained by the slidino- tube, and fixed to any point by the tightening screw ; on the contrary, the nearer the object and shorter the instrument, the smaller the drawing. The sliding tube is divided for the purpose of ascertaining the height of the instrument, should the draAving not be finished at one time. Some little attention is necessary to the position for taking profiles, sketching flowers, &c. Darken one half of the window to shade the instrument, and place the object on the opposite part of the table in the light, having the table close to the window; the latter always to the right hand, as in the manner usually adopted by artists when taking likenesses. The eye-hole should be kept closed when the instrument is not in use. Should the mirror become dull from the damp or dust, remove the bottom by means of the screw. Slide the front glass gently downwards for the purpose of cleaning the mirror. Care being taken, the instrument will be as perfect as ever. Price, $10.00 and $12.00. Fis-708- Polemoscope. — (Fig. 70f.)—A re- flective perspective glass, invented by Hevelius, who re- commends it as use- ful in sieges, placed in the square hole prepared for it; the light passes the plano- conArex lens, strikes the picture, and passes to the smaller lens, whence it is cast on the white wall of an apartment, or a sheet, or other screen. A better Avay of glassing the lantern is described under the article " Improved Phantas- magoria Lantern." These magic lanterns are handsomely japanned, having oil lamp, reflector, a set of twelve sliders with mahogany frames and box. Price, with 2 inch lenses, $ 5.50. " " 2| " " $ 8.00. " " 31 " " $10.50. " 4 " " $16.00. Phantasmagoria Lantern.—(Fig. 732, next page.)—The phantasmagoria lantern differs in no degree whatever from the above, except the lenses being larger and the tube holding them is made so as to project beyond the outer lens, and the lens itself is made to slide readily and evenly backwards and forwards, either by means of a rack and pinion, or more simply by little studs, fastened on each side of it, Avhich pass through the sides of the tubes, and are moved along by means of the finger. It also contains a powerful solar lamp. Price, $15.00. - MAGIC LANTERNS. 205 Fig. 732. Improved Phantasmagoria Lantern, with a Solar Lamp.— The magic lantern, which was formerly used merely to amuse children, by the exhibition of miserable caricatures and grotesque figures, has of late years assumed a different character, by being adapted to the representation of subjects of natural and scripture history, botany, astronomical dia- grams, the costume of different countries, &c. With the view of rendering the magic-lantern a source of highly in- structive amusement as well as entertainment, the writer has produced, at a considerable expense, a variety of sliders of a very superior order. With these sliders the phantasma- goria lantern will become not only a most amusing and ra- VOL. II.—18 503368 206 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. tinual recreation, but a powerful auxiliary in the work of education. There is, perhaps, no better method of giving young people a greater knoAvledge of a variety of subjects, and particularly of the different branches of natural history, than by Avell colored plates, accompanied with a short ac- count of the subject. Besides, the very nature of the exhi- bition is calculated to excite the attention, and impress the imagination, and many a lesson in natural history, astrono- my, &c, may be given and impressed on the mind in such a Avay as not to be forgotten, while the pupil supposes he is merely amused. A great deal might be said of the advan- tages attending this mode of instruction, but it is presumed that sufficient has been said to draAv the attention of the public to it; and there is no doubt, that the judicious pa- rent and enlightened instructor will fully appreciate its merits ; indeed, its extensive introduction into infant schools and the lecture room, sufficiently proves its great utility for the purposes of education. The cut (Fig. 733, following page) represents one of the improved phantasmagoria lanterns ; a tin box fifteen inches high, ten long, and seven and a half wide, having two double convex lenses mounted in a brass cell, and kept in by a counter screw and slip into a short tube soldered inside the lantern; the painting is slid in an aperture close to the two lenses and is kept in its place by a heliacal spring. There are two double convex lenses to magnify the picture; they are screwed into a brass tube, Avhich slides in a short spring tube. The other end is contracted by a stop, which, by cut- ting off some of the extreme rays, renders the image more distinct, though it lessens the quantity of light; in some subjects the light may be thought of the most importance, and the stop is therefore made to unscrew. This lantern has met with the approbation of the most eminent opticians, as Avell as every other person who has either examined the principle on Avhich it is constructed, or witnessed its effect. The addition of a solar lamp renders the images much more brilliant and distinct, and of course they can be more mag- nified. The lamp is of a very simple construction, and can never be out of order, and can be easily emptied ; a great advantage for this particular purpose. The lantern is con- structed so that the lamp receives a plentiful supply of air from without, and not from the inside of the lantern, as is generally the case, the consequence of which is, if the lamp MAGIC LANTERNS. Fig. 733. burns brilliantly and without smoke when out of the lantern, it is sure to do so when in it; the improved phantasmagoria lantern possesses a great superiority over those generally made of equal power. Price, Avith 3 inch lenses, $14.00. " 3i " " $15.00. " 4 " " $18.00. To use the Phantasmagoria Lantern.—Trim the lamp with the finest spermaceti oil, and make it burn brilliantly; take care it does not make the least smoke, to prevent which, it is necessary that the top of the cotton should be kept perfectly even, which is made so in a very simple manner, by putting the cotton upon the bucket, then wind- ing it down into its place, and burning off the cotton that 208 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. projects, previously to putting oil in the lamp ; it is impossi- ble to cut the cotton so true as it will be by the plan men- tioned. The cotton should now be taken out, and the lamp filled Avith oil; the top of the cotton should be then dipped about an inch into the oil ; if this is not attended to, the cotton Avill not possess the power of drawing up the oil to the flame sufficiently. Now place the lantern on a table, about eight or ten feet from a white Avail; the further the lantern is from the wall, the lyrger will be the image, and the contrary ; if the wall is not Avhite. a sheet may be sus- pended against it; the room being made as dark as possible, sit down to the table with your face towards the wall or sheet, and putting a slider through the slit with one hand, slide the brass tube in or out Avith the other, till the image of the painting is perfectly distinct on the Avail; take care to keep the painting in the centre, or only part of it will be visible, and it should also be kept against that side of the slit which is next the light. Every slider should be put in the same way, viz. with the right or lettered side towards you, and the paintings inverted. Instead of placing the lantern on a table, it is often more convenient to hold it under the arm, or it may be fastened round the waist, as directed for the phantasmagoria, taking care to keep it upright; the natural history subjects may then be given in their natural sizes with the utmost facility. Besides the foregoing directions it may not be amiss to mention the following particulars, which if not attended to, the figures will be dull and indistinct. 1. The lenses must be quite clean and free from dust, and Avhat is still Avorse, damp. If any appears between them, the glasses should be separated, and Avell wiped with a piece of wash-leather, or a clean dry linen cloth. If the lantern has stood for some time it will be always necessary to do this previously to exhibiting it. 2. The glass of the sliders should never be soiled with the fingers, and if dusty must be Avell Aviped, taking par- ticular care to go over the painted side very gently. 3. The lamp must be made to burn brilliantly, and the lantern should not be used till that is found to be the case. It is much better to trim the lamp every time an exhibition is made, and never to use the lamp or cotton if they have stood with oil any length of time; it is recommended that the lamp be always cleaned before putting away. MAGIC LANTERN- 209 Directions for exhibiting the Phantasmagoria.—(F\g. 734.) —For this purpose, instead of the image being exhibited on a white wall or sheet, it is thrown on a transparent screen placed between the spectators and the lantern. The screen not being seen, the image appears to be suspended in the air, and when the image is increased or diminished, it appears to the spectators to approach or recede from them. Ihe deception is so complete, that even those who are accus- tomed to the exhibition, and know where the screen is placed, are deceived by it. For the production of this very amusing and striking exhibition, no additional apparatus is necessary, except a transparent screen. This has usually been made of silk or muslin, either varnished or coated with a mixture of turpentine and beeswax. These screens are not only expensive, but very soon get injured and dirtied. The folknvino- is a very simple method of making an excel- lent one ; instead of varnishing the muslin, it is only dipped in water, and hung up quite wet. A screen of this kind costs but a trifle, can be folded up in small compass, and when soiled is easily made clean ; so far from having any disadvantage to counterbalance these advantages, it is superior in effect to any other, and has this peculiar and great convenience, that it requires no stretching and hangs more level than any other. The muslin it is made of should be of the closest texture, and need not be very fine, ltie screen should be hung on a frame, and being wet will require no fastening; the frame itself may be made so as to take to pieces and tie up together in a small compass. Ihe screen being prepared, should be so placed in the room as to leave space enough for the spectators, without their being too near it. If there is a door between two rooms, the screen may be suspended from the door frame ; this is a very convenient method. . The person who manages the lantern must fasten it to his middle with a leather strap passed through the loop, sol- dered to the back of the lantern, and holding the lantern with one hand, adjust the tube with the other; he should now go up pretty close to the screen, and draw out the tube till the image is perfect; which of course will be very sma 1; then walking slowly backward, and sliding the tube in at the same time to keep the image distinct; as it increases in size, it will appear to the spectators on the other side the screen to be coming towards them, and then again by walk- 210 BENJ. PIKF.'s, JR., DESCRIPTIVE CATALOGUE. Fig. 734. MAGIC LANTERNS. 211 ing towards the screen to diminish the image, it will appear to them as if it was receding. The only difficulty in making this exhibition, is in sliding the tube in or out properly to keep the image perfect: no rule can be given that would be of any service, but the operator will soon perceive that when the image is got to a moderate size, the tube requires to be slid in very little to in- crease it; but when the image is about four or five inches diameter, to reduce it to one half that size, the tube will re- quire to be drawn out more rapidly : practice alone will enable him gradually to reduce or enlarge the image, and at the same time to keep it distinct. To give Motion to the Images.—A variety of movable sliders are made for this purpose, many of which produce very curious appearances, but with the usual sliders the images may be made to move in a circular, elliptical, or other direction, by moving the lantern in the corresponding way, which will of course produce the like motion in the images. A curious effect is also produced by drawing out the tube and slipping it in suddenly to the focus ; this is easily done by holding the tube tight at the proper place. A shivering motion may be given to the images by giving the lantern a sudden shake. By standing at the bottom of a pair of stairs, a figure may be made to appear going up, by giving the lantern a slight angular motion ; the figure of the skeleton is a very good one for this purpose : in the same way this figure may be made to lie on the floor and rise up to a sit- ting or standing posture. By combining the motion of the lantern with movable sliders, a great variety of curious effects may be produced, particularly on the transparent screen ; many of these are often exhibited in public, and from what has been said, those Avho take pleasure in this machine, will soon be able to produce most of them. Description of Carpenter's Improved Lucernal Microscope. —This microscope is used to exhibit transparent objects on a scteen or white wall, in the manner of the solar micro- scope ; though from the difference in the intensity of the solar light and that from a lamp, the effects are very infe- rior. The lucernal microscope has, however, some advan- tage over the solar; it can be used by night, and in the long evenings, when amusements are most necessary ; it is more 212 BENJ. pike's, jr., descriptive catalogue. simple in its construction, and easier to manage; and even when combined Avith the improved phantasmagoria lantern, is less expensive than the commonest solar microscope. Objects may be magnified by this microscope from a feAV inches to eight or nine feet diameter, or even more, but most objects appear best when magnified from three to six feet. The screen, if there is no white wall, should be made of large drawing-paper, strained tight on a frame. The screen used for the phantasmagoria, or a window blind, will answer, but not so well as one made of paper, many of the finei parts being rendered indistinct by the irregularities of the surface, and also from much of the light passing through the screen instead of being reflected from it. By the addi- tion of a plane mirror, fig. 3, plate 735, set in a brass frame, which screws on the magnifier tube, objects may be thrown on a sheet of paper placed either on the floor or on the table, or they may be reflected up to the ceiling. To use the Lucernal Microscope.—(Fig. 735.)—It is repre- sented in the plate attached to the improved phantasmagoria lantern, in which way it is generally made, though it may be constructed to act as a microscope only. Unscrew the brass plate which fills up the hole in the back part of the lantern, and screw the microscope, fig. 2, in its place; see fig. 1. Having made the lamp burn brilliantly, and the lantern being placed on a table about four or five feet from, and directly opposite the screen, push in one of the sliders with objects, fig. 4, between the spring plates, and adjust the magnifiers to the focus, by turning round the tube in which they are fixed. It is hardly necessary to remind the operator that the lenses should be perfectly clean, and the room as dark as possible, as upon these circumstances in a great measure depends the perfection of the image. If you Avish to make a drawing of the image, place the lantern on a hio-h stool upon the table, and screw the frame, tig. 3, into the front part of the microscope, by turning it round so that the mirror be below ; the image will be represented in a very beautiful manner on a sheet of paper placed on the table to receive it, and an accurate outline may be taken of it, even by those unaccustomed to the use of the pencil. By brino-- ing the tube of the microscope beyond the edge of the table, the image may be reflected on the floor, and by turnino- it MAGIC lanterns. Fig. 735. 213 214 benj. pike's, jr., descriptive catalogue. upwards the image is represented on the ceiling. The image may be made of different sizes by removing the lantern further from, or nearer to the screen ; for in proportion as the distance is increased the image is enlarged, but at the same time becomes fainter. When the microscope is used the tin cap should be pushed over the large lenses of the lantern, to prevent the light from escaping. The following is a list of the objects best adapted to this microscope :—Cuttings of woods and herbaceous plants, par- ticularly such as have large pores ; wings of insects ; scales of fish ; the cast skins of spiders and other insects, snakes, lizards, 145, pair of glass plates for attraction of cohesion, $1.50 ! 148, set of tubes for capillary attraction, 50c ; 123, planeta- rium, $7.50. $10.50. Optics.—Fig. 731, magic lantern and 12 comic sliders, $8 ; 751, compound microscope, $4; 702, camera obscura; $3.50 ; 698, prism, $1; 699, color blender, $1 ; kaleidoscope, 50c ; set of lenses, If inch diameter, $1.25 ; concaA'e and convex mirror, 5 in. diameter, $2.25 ; multiplying glass, 50c. $22.00. Electricity.—Fig. 272, electrical machine, Avith • 6 inch cylinder, Avith knob, two chains, and box of amalgam, $12: 276, Leyden jar, $1.25 ; 277, discharger, $1.25 ; 296, bells, $2.00 ; 300, pair of image plates and pith images, $1.25 ; 302, one dozen pith balls, 25c.; 305, long hair man, 75c ; 315, horsemen, $2.50; 320, swan, 50c; 322, syphon and bucket, $1 ; 335, luminous spiral tube, $2. $24.75. Pneumatics.—Fig. 183, single-barrel air-pump, Avith bell- receiver, $12 ; 191, hand and bladder-glass combined, 75c ; 211, air shower, 75c. ; 212, mercury cup, 75c. ; 195, pres- sure glass, 75c ; 197, Magdeburgh hemispheres, $4 ; 200, fountain, $4 ; 206, bladder and weights, $1.75 ; 218, bell, $2.25. $27.00. Hydrostatics, dec.—Fig. 248, syphon, 75c ; 102, spirit level, $1 ; 238, hydrometer, 75c; 259, hydrostatic bellows, $5 ; 252, lifting pump, $3. $10.50. Galvanism and Magnetism.—Fig. 400, Grove's battery, with apparatus for the decomposition of water, charcoal points, &c, $12 ; 391, pot battery, $2.50 ; 424, electro- magnet, $1.50 ; 426, magic circle, $1.75 ; 407, powder cup, 274 BEXJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 75c ; 469, magneto-electric machine for shocks and sparks, $9.50; 410, magnet, 75c; 418, star plate, 50c; 6 inch magnetic needle with mariner's card, $1. $30.25. Chemistry.—Fig. 514, retort stand, $1.50; 511, spirit lamp, 75c. ; 482, three flasks, 25c ; 484, three assorted re- torts, $1 ; 489, one receiver, 38c ; 483, one matrass, 38c. ; 522, pneumatic cistern, $2; 481, tAvo bell glasses, quart and half-gallon, $1.25 ; stoppered gas bottle, half-gallon, 63c ; 525, bell glass, Avith cap, stop-cock, jet, pipe, and gas bag, $2.75; 540, gas pistol, 39c; 508, bloAvpipe, 38c; 500, dropping tube, 38c ; 494, funnel, 15c; 512, mortar 75c; 507, evaporating dish, 38c. ; 509, nest of crucibles, 10c ; 495 grade measure, 63c; 237, scales and Aveights, Si.25; 493, two precipitating glasses, 31c ; 502, three°test tubes, 15c; 504, air thermometer, 19c; Torricellian tube, 75c; 555, pyrometer, $3.50 ; 552, conductometer, $1.75 ; 556, condenser, $1 ; 542, eolopile, 38c ; 543, boiling glass, 50c; 560, Wollaston's steam apparatus, $1.50; 540, hy- drogen gas pistol, 38c $25.59. Total, $150.00. Or, with the addition of the following, $250. Figs. 154, 155, 156, and 158, set of mechanic powers, $16; 147, four and a half inch surveyor's compass, $14; 180, double barrel air pump, in place of single barrel air pump, $22,50; 208, piston Aveight lifter, $6 ; 260, vessel for spouting fluids, $4 ; 267 or 270, plate electrical machine, m place of cylinder electrical machine, $25 ; 536, compound blow pipe and pneumatic cistern combined, in place of pneu- matic cistern, $8 ; 733 and 740, superior magic lantern and set of astronomical sliders in place of magic lantern and comic sliders, $35; 604, barometer, $10. 23* MATHEMATICAL INSTRUMENTS. 275 APPROVED SET OF PHILOSOPHICAL APPARATUS FOR $600. Fig. 144, inertia apparatus, $1.50; 145, pair of plates for attraction of cohesion, $1.50 ; 148, set of tubes for capillary attraction, $1 ; 150, set of five ivory balls for col- lision, $1.25; 153, 154, 155, 156, 157, set of mechanical powers, $35 ; 123, planetarium, $7.50; tellurium, $6.50; 95, quadrant, $15: 92, surveyors' compass, $20; two pole surveyors' chain, $1.25. $90.50. Optics.—Fig. 698, large prism, $1.50 ; 699, apparatus for the recomposition of light, $1 ; set of four lenses, two and a half inches diameter, $6 ; multiplying glass, 50c ; 694, 695, 696, 697, set of four eye models, $13 ; 702, camera obscura, $3.50 ; 701, cosmorama and tAvelve views, $4.25; pair of six inch mirrors concave and convex, $3.50 ; 752, large compound microscope, $19 ; 733, magic lantern, $15 ; 740, set of astronomical sliders for the magic lantern, $20; six comic sliders for magic lantern, $7.50 ; sliders re- presenting blooming carnation, $1.25 ; death on the pale horse, $1.25. $94.75. Electricity.—Fig. 270, twenty inch plate electrical ma- shine with mahogany frame, $38 ; 276, Leyden jar, $1.25 ; 277, discharger, $1.25; 291, battery of four quart jars, $6.50 ; 281, quadrant electrometer, $1.25 ; 275, insulating stool, $3 ; 296, bells, $2 ; 300, plates and dancing images, Si.25; 294, magic picture, $1.75; 305, long hair man, 75c; 302, one dozen pith balls, 25c ; 316, orrery, $2.50 ; 314, horsemen, $2.50; 332, aurora tube, used also as guinea and feather tube in pneumatics, $6 ; 335, spiral tube, $2.50; 337, luminous word, $3; 322, bucket and syphon, $1; 345, pistol, $3 ; 341, fire house, $4. $81.75. Pneumatics.—Fig. 177, best lever air pump with maho- gany frame, $70; 188, bell receiver, $2; 217, open top 276 benj. pike's, jr., descriptive catalogue. receiver, $2.50 ; 217, plate with slide rod, $2.50 ; 191, ban* and bladder glass, 75c ; 211, air shower, 75c ; 212, mer- cury cup, $1 ; 195, pressure glass, 75c ; 190, bolt head experiment and jar, $1.25 ; 197, Magdeburgh hemispheres, $5 ; 200, fountain, $5 ; 208, weight lifter, *6 ; flexible tube, $2 ; 214, globe to Aveigh air, $1.75 ; 219, bell, $2.50 ; 222, Torricellian experiment, $3.50; 225, freezing apparatus, $1.75; 228, flint and steel in vacuo, $5 ; 235, water hammer, 75c; 185 or 186, condensing apparatus with jets, revolving jet, air gun barrel, &c, $13.50. $128.25. Hydraulics and Hydrostatics.—248, syphon, 75c ; 249, Wirtemberg syphon, 75c ; 102, spirit level, $1 ; 238, hy- drometer, 75c ; 250, Tantalus cup, $2 ; 252 and 253, lift- ing and forcing pump in frame, $10; 255, instrument to show the rise of water to its level, intermitting springs, &c, $7.50; 259, hydrostatic bellows, $5 ; 260, vessel for spout- ing fluids, $5. $32.75. Galvanism, Magnetism, dr.—400, Grove's battery, tAvelve series, large size, with glass vessel for collecting gas ; 402, charcoal points, &c, $18; 391, cylindrical pot battery, $2.50 : 424, electro-magnet, $1.50 ; 420, magic circle, $1.75; 427, iron rod supported in air, $2 ; 407, powder cup, 75c ; 431, CEisted's experiment, $3.50: 432, galvanometer, $3.50 ; 428, magnetizing helix, $2.50 ; 449, wheel engine, $6.50; 452, beam engine, $12; 410, horse-shoe magnet, $1 ; 86, mariner's compass complete, $2.50; 418, star plate, 50c ; 418, revolving armature, $1 ; 418, Y armature, 50c ; 418, cross bar armature, 75c ; soft iron rods, links, filings, 25c 860.50. Chemistry.—Figs. 484 and 485, six glass retorts, assorted sizes, three of them stoppered, $2.25 ; 489, two receivers, 75c ; 483, two bolt heads, 68c; 482, six flasks, 50c ; 481, three bell glasses, one quart, one half gallon, and one gallon, $2.25; one stoppered do., half gallon, $1 ; two wide mouth glass jars Avith stoppers, for receiving gases, Si ; 487, iron retort, $2 ; eight feet of small lead pipe, 50c.; 514, retort stand, $1.50 ; 511, spirit lamp, 75c ; 499, glass tubes, 25c ; 493, three precipitating glasses, 50c; 494, funnel, 15c; 495, graduated measure, 63c; 502, six test tubes, 31c; 504, air thermometer, 19c ; Torricellian tube, $1; 509, nest MISCELLANEOUS INSTRUMENTS. 277 of crucibles, 10c ; two evaporating dishes, 72c ; 512, mor- tar, $1 ; 536, compound blow pipe with pneumatic cistern, $8; 525, bell glass Avith cap, two stop-cocks, union, jet, pipe, and gas bag, $4 ; 408, blow pipe, 38c ; 539, hydro- gen generator, $5; 540, hydrogen gas pistol, 38c ; 541, air balloon, $1.25; 542, eolopile, 88c; 547, pulse glass, 50c ; 548, boiling glass, 50c ; 546, flameless lamp, $1.50; 552, conductometer, $1.75; 555, pyrometer, $3,50; 556, condenser, $1 ; 559, Marcett's steam boiler, $15 ; 560, Wollaston's steam apparatus, $1.50 ; 549, chryopherus, $1.75 ; 572, Woulfe's bottle, $1 ; bent glass tube, 25c $79.81. Meteorological.—Fig. 604, barometer, $10; 587, ther- mometer with Fahrenheit and centigrade scales, $1.50 ; 591, day and night register thermometer, $4 ; 619, Mason's hygrometer, $5 ; 622, conical rain gauge, $2.50. $23.00. Set of minerals, 144 specimens, arranged in three trays and mahogany box with lock, $12; set of geometrical solids, $1.25. $13.25. Or, with the addition of the following, $1000. Fig. 130, astronomical telescope, $65 ; 757, solar micro- scope, $50; 99, theodolite, $100; 176, Atwood's appara- tus for laws of falling bodies, $100; 168 to 174, whirling table and apparatus, $75 ; 455, bell engine, 12.00. vol. n.—24 GLOBES AND SETS OF SCHOOL APPARATUS, MANUFACTURED AND SOLD By BENJAMIN PIKE, Jr., 294 BROADWAY, NEW YORK. The artificial globe is a round body or sphere, having on its surface a map of the earth, or of the celestial constellations, as delineated, with the principal circles of the sphere. In the former case it is called the terrestrial, in the latter the celestial globe. Artificial globes are used for the purpose of conveying to young persons the first ideas of the figure and rotation of the earth, of* lat- itude and longitude, and the situation of places Avith respect to each other, and to the sun at different seasons of the year. It is usual to employ them also for the purpose of solving mechanically elementary problems of astronomy, relative to the difference of the hour of the day at different places, the times of the rising and setting of the sun, the limits of the visibility of eclipses, &c. The fundamental parts of these instru- ments, which are common to both, are, first, the two poles whereon the globe is support- ed, representing those of the world ; second, the brazen meridian, Avhich is divided into degrees, and passes through the poles; third, the wooden horizon, whose upper side repre- sents the real horizon, and is divi- ded into several circles ; fourth, a brass quadrant of altitude; fifth, two hour circles, one moving round each pole as a centre, and divided into twice twelve hours, to indicate those of the day and night. Upon the surface of the globes are de- picted the lines of latitude and longitude, the equator, ecliptic, tropics, and polar circles. On one globe, in addition to these, are the various countries, seas, &c, of the world; and on the other, the stars in their relative positions. Terrestrial and Celestial Globes, 9, 12, 18, and 36 inches diameter, made by Malby & Son, London, GLOBES. 279 under the superintendence of the Society for the Diffusion of Useful Knowledge. 9-inch Globes, Celestial and Terrestrial (the pair), $16 00. 12-inch " " " " 20 00. 18-inch " " " " 48 00. :tfi-incli " " " " 200 00. A Glolie Quadrant accompanies each pair. 18-inch Ten estrinl Glolie......$25 00. | 36-inch Terrestrial Globe......S105 00. In these globes an endeavor has been made to combine a degree of accuracy, such as is only possessed by the best modern maps, Avith the lowest price at Avhich excellence can be attained. The terrestrial globe has been compiled from the most recent geographical surveys, with the aid of the accounts given by the best travellers. The astronomical information which has been supplied of late years upon the position and nomenclature of the fixed stars, has rendered a perfectly new celestial globe a most desirable acquisition to the stu- dent of astronomy. The labors of Piazzi, Bradley, Lacaille, Johnson, &c, in determining the places of the stars, and those of Baily in the correction of their nomenclature (in the new edition of the "British Catalogue"), have been carefully consulted in the celestial globe which is now advertised. The stars in the northern hemisphere are all which are given by Piazzi, with the addition of such of Bradley's (from the Tabula Regiomontanoz) as are not in Piazzi. The stars in the southern hemisphere comprise all those given by Lacaille and Johnson. SLATE GLOBES. Mi.lby'8 12-inch Slate Globe......$10 00. | 18-inch Slate Globe............$25 00. AMERICAN GLOBES. 3-inch Terrestrial Globe.........$ I 00. I 10-inch Terrestrial Globe......$10 00. 5-inch " " .........150. 13-inch " " .......13 00. 9inch " " .........8 00.| 9-inch Celestial and Terrestrial Globes (pair) $16 00. 10-inch " " " " 18 00. 13-inch " " " " 25 00. 16-inch " " " " 40 00. Terrestrial Globes, nn neat Mahogany Bases, Inclined Axis, without Horizon: 3-inch, 75 cents ; 5-iuch, $1 25 ; 7-inch, $3 25. ENGLISH PEDESTAL GLOBES (Very Neat). 3-inch (the pair).................$3 50 I 6-inch (the pair)................$8 00. 5-inch " ..................650.|9-inch " ................15 00. 13-inch Globes, with High Mahogany Stands and Compasses (the pair)---$40 00. 18 inch " " '• " " " $68 to $80. 18 inch " " Rosewood " " " $100 00. Globes in neat Mahogany Cases: 1-inch Terrestrial, 75 cents ; lj-inch, $1 00; 2-inch (the pair), $:) 00. Mattison's Astronomical Maps, size 38 by 45 inches, on Cloth and Rollers, at $16 50 the set. Astronomical Diagrams for the Magic Lantern, ot every variety and size. 2^0 BEXJ. PIKE'S, JR., DESCRIPTIVE CATALOGIE. SET OF APPARATUS FOR MOTION, MECHANICS, AND MATHEMATICS. Price $72 00. 1. Inertia Apparatus.....$1 50 2. Collision Balls and Frame - - - - 3 00 3. Apparatus for Impenetrability - - - 1 00 4. Adhesion Plates......1 50 5. Capillary Tubes......1 00 6. to 10. Set of Mechanical Powers - - - 16 00 11. Rocking-Horse......0 75 12. Planetarium.......7 50 13. Centrifugal Machine.....4 50 14. Surveyors' Compasses, 5 inches diameter - 18 00 15. " Chain, 2 poles - - - - 1 25 16. Quadrant.......15 00 17. Hour-Glass......1 25 The Mechanical Powers, figures 6, 7, 8, 9, and 10, consisting of levers and pulleys, arranged on a mahogany frame, 24 inches long 26 inches high, with four systems of pulleys attached. On each side of the frame, behind the pulleys, are graduated scales, with cords pas- sing across the length of the frame and dividing the space into 24 equal parts, to show the number of inches, rise and fall, of the weights, and that it is inversely as the power gained. Brass levers on the top of the first, second, and third orders; bent lever and pulley for passing over the cord; and on one end is fixed the wheel and axle, with four different diameters. The accompaniments are : A large and well-made inclined plane, with graduated arch and carriage, wedge jointed in two parts, screw and lever, and screw as an inclined plane; and a set of 10 brass weights, from one quarter of an ounce to eight ounces. Price $16 00. Also Larger Sets, at $33 and $60. Atwood Machines, at $2."), $40, $100, and $120. Whirling Tables and Apparatus, $30, and $75. SCHOOL APPARATIS. 281 SET OF APPARATUS FOR OPTICS. Price $163. .^1: 1 Set of Six Lenses............$1 50 1. 2. Prism 3. 0 75 Color-Blender................1 00 Pair of 5-inch Mirrors, Concave and Convex................2 25 MulliplyingGlafs..............0 38 Camera Obscura .............4 00 Cosmorama and 12 Views......4 25 Model of Eye..............] Muscl.-s of Eye........---• I 13 00 L..HL' & Short Sight Explain, j Iina>;e on Retina...........J Simple Microscope............1 00 13 Compound Microscope.......$3 50 14. Solar " ............28 00 15. Astronomical Telescope, with 3-inch Achromatic Olvject- Glase. and about 5 feet long on Stand...........■........48 00 16. Magic Lantern..........$3 to 15 00 17 One Dozen Sliders......$2 to 15 00 ' Set A«tronom. Sliders $7 50 to 20 00 18 Polarisc-op- .............. Crystals f..r Polari.-cope ...1 00 $1(53 31 A good Compound Microscope may be had for $3 50; larger, $5 50, $9 50, $10, and S20. Superior Magic Lanterns SI a ; Sliders, 4 inches wide, on Astronomy, $20 the set; Natural History, $20; Botany $20; Scripture History, $27 50; Humorous and Comic Sliders «1 25 each. Also, Views and other subjects in great variety. A pair of Lanterns, with Dissolving Apparatus, $50 Astronomical Telescopes, with Mahogany Tube, on Stands acconlmg to size, $30 to $48. Others of various kinds and styles, with Brass Tubes, vary- no- from $25 to $400. The Eye Models in four parts : A D.ssected Eve four inches diameter, showing the cornea, ins, ciliary process choroid tunic, crystalline lens, vitreous humor, retina, black pigment, optic nerve, &c.,"and the eye in its socket with the muscles ; the Eye, with the rays of light passing from an object and forming the image on the retina; the object and image moveable showing the cause of fong sight, short sight, and perfect s ght; and a 4-.nch ball with convex lens on one end, and a ground glass fixed to a sliding brass tube on the other end, and on which may be seen the inverted image representing the eve as a camera obscura, and by the aid of the set ot lenses, the use of spectacles to the eye explained, 282 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. SET OF PNEUMATIC APPARATUS. Price $42 00. Consisting of a Double-barrel Air-Pump, worked by racks and cog-wheel, by double lever handles, mounted on a polished mahogany frame. Price $23. 2. Swelled Air-Pump Receiver - $1 75 3. Hand and Bladder-Glass - 0 75 4. Pressure-Glass..... 0 75 5 Fountain in Vacuo .... - 4 00 6. Bell " and Receiver 2 25 7. Flask, Avith Stop-Cock, to weigh Air - 2 00 8. Freezing Apparatus and Loav Receiver 1 50 9. Bolt-head Experiment - - 1 25 10. Air Shower Experiment 0 75 11. Magdeburg Hemispheres 4 00 With the above-represented Air-Pump, and ten different appen- dages, many interesting experiments may be performed, and all the most important connected therewith, illustrated in a satisfactory man- ner. All but the last two are drawn in the cut. On the right of the cut is represented a brass Condensing Pump, the barrel ten inches long, and one and a half diameter, and a strong glass Air-Chamber, with cap, stop-cock, and pipes, attached; also, a Revolving Jet, Straight Jet, and Rose Jet; the whole being a complete apparatus for the condensation of air and experiments therewith. The jets may be used bv the passage of either air or water through them, price $12. An apparatus with cylindrical copper air-chamber, at the same price. Also, a Brass Tube for illustrating the principle of the Air-Gun, price $1. f0' „Tne Air-Purnp apparatus, or any portion of it, may be used with a Single-Barrel Air-Pump, at $7, $9, or $12, according to size ■ or with Pike's Improved Single-Barrel Air-Pump, price $20 being the largest, most powerful, and durable pump made for the' price SCHOOL APPARATUS. 283 with Also, Pike's elegant Lever Air-Pumps, 4 feet high, price $63, or with gauge, $70; larger Double-Barrel and Lever Air-Pumps, and more extended apparatus constantly on hand. SET OF APPARATUS FOR HYDROSTATICS. Price $45. .,-■Ti 2 1. Hydrometer - - " " ' ' $?5n 2 Tube for Relative Weight of Fluids - - 150 3. Level and Plumb-Level - - - - l £ 4. Syphon with Drawing-Tube - - - " " i? 5. Wirtemberg Syphon....." .....19 cts. to 0.38 18 Dividers, from four to seven inches, steel joint, _. ,. 31 cts. to S0.63 19 Ruling pens, common, with brass handle, 25 cts. to 0.38 20 Ruling pens, good quality, with ebonv handle, 0 75 MATHEMATICAL INSTRUMENTS. 3 No. ., 21 Fig. 9, ruling pens, best quality, turn up nibs, ivory handle, - - - " • 22 Fio- 10, rulincr pens, best quality,ivory handle, l.i.o 23 Ffe 11 roadmen, - - - *3.00 and 3.50 24 Fig. 5 and Fig. 12, dotting pen, - $2.25 to 6.00 25 Fig. 13, needle holder, - - - - ]-25 26 Bow compasses, in brass, $1; in German silver, 1.38 27 Fig. 15, bow pen, in brass, $1, in German silver, - - - " " " ' 28 FiUU 237 Fig. 149, pair of glass plates for capillary at- traction, ..... 238 Fio-. 150, collision balls, set of five in ivory, four sizes, - - $1-25, 2.00, 3.00 and 4.50 239 Fio-. collision balls mounted on frame with arch,......$7to 12-00 240 Fig. 150, set of five boxwood collision balls, 1-00 241 Fw. 150, set of five boxwood collision balls, and frame with arch, - - $3.50 to 7.00 242 Fio- 151, machine for showing the composi- tion of forces, - - - - °-uu 243 Fig. 152, rocking horse for illustrating the centre of gravity, - - - - 10° 244 Fio-. 152, a pair of mahogany blocks with wires for centre of gravity, - - - I-00 245 Figs. 153 to 157, set of mechanic powers, with graduated framework, six systems of pulleys, wheel and axle, levers of first, second, and third order—compound levers, bent levers, screw with lever—inclined plane with graduated arch, carriage wedge in two parts, and a set of brass weights, 35.00 12 BENJ. PIKE'S, JR., PRICE CATALOGUE. No. 246 Figs. 154, 155, 156, and 158, set of mechanic powers, with graduated framework, four systems of pulleys, wheel and axle, levers of first, second and third order—bent lever, screw with lever, inclined plane with gradu- ated arch, carriage wedge in two parts, and a set of brass weights, - $16.00 247 Fig. 159, 160, 161, 162, and 163, improved and elegant set of mechanic powers, con- sisting of a complete set, with an apparatus for the composition and resolution of forces. The whole mounted on four polished maho- gany frames, uniform in their size and finish, 60.00 248 Fig. 164, screw press, - 2.25 249 Fig. 165, endless screw, - - - $6 and 8.00 250 Fig. 166, capstan,.....2.50 251 Fig. 167, double cone, - - $1.50 and 2.00 252 Fig. 167, double cone with adjusting screws, 3.00 253 Fig. 168 to Fig. 174, whirling table, for ex- plaining and demonstrating the laws of the planetary motions, and other properties of gravity and centrifugal forces, - - 75.00 254 Fig. 175, whirling table of simpler construc- tion, with the apparatus represented in Figs. 169, 170, 171, 172, 173, and 174. 30.00 255 Fig. 176, Atwood's elegant and accurate ap- paratus for demonstrating the laws of acce- lerated and retarded motion, and other in- teresting laws in mechanics, with clock beating seconds, ----- 100.00 256 working model of steam engine, - $35.00 to 90.00 PNEUMATICS. AIR PUMPS AND APPARATUS. 257 Fig. 177, improved lever air pump, with mercury gauge and polished mahogany frame, ----... 70.00 PNEUMATICS—AIR PUMPS AND APPARATUS. 13 258 Fig. 177, ditto, with rosewood frame, - - $ 75.00 259 Fig. 209, small size lever air pump, barrel eio-ht inches long and two and a half inches diameter, ------ 20-00 960 Fio-. 178, French table air pump, frame all brass, large size, - - - to.w 261 Fig. 178, ditto, second size, - - - 50.00 262 Fi°. 179, double barrel table air pump, large siZe, ----- $40 and 45.00 263 Fio- 180, double barrel table air pump, small size;.....$22.50 and 25 00 264 Fig. 181, Pike's improved double barrel air pump, $65; in rosewood frame, - - 70.00 265 Fig. 182, single barrel air pump, small size, 7.00 266 Fig. 182, " " " " medium size, 9.00 267 Fig. 183^ " " " " large size, 12.00 268 Fig. 184, Pike's improved single barrel air pump with raised plate, - - - 18.00 269 Air pumps, small size, without plate and stand, &c.,.....$3 to 5.50 270 Fig. 185, improved condensing apparatus with glass chamber, ----- 10.00 271 Fig. 186, improved condensing apparatus with copper chamber, _ - - - 10.00 272 Either of the two last with revolving jet, - 12.00 273 " " " " " " an(* air gun barrel, ----- 13.50 274 Fig. 187, lever condenser on frame, - - 20.00 275 Fig. 188, swelled air pump receivers, four Inch, 75cts.; five inch, $1; six inch, $1.25 ; seven inch, $1.50; eight inch, $1.75; nine inch, $2 ; ten inch, $2.50 ; twelve inch, 4.00 276 Fio-. 189, low receivers for the air pump, five ?nch, 75 cts.; six inch, $1; seven inch, $1.37 ; eight inch, - 1-75 277 stop-cocks for air pump, three inch, - - 1.00 278 Connecting screws, guard screws, &c, each, 0.50 279 Fio-. 190, gallows connector, - 1-50 280 Figs. 191 and 192, hand and bladder glass, 0.75 281 Fig. 193, bladder glass with cap and stop- cock, .......20*j 282 Fig. 194, apple cutter, - 1.50 14 BENJ. PIKE'S, JR., PRICE CATALOGUE. 283 Fig. 195, pressure glass, - - - - $ 0.75 284 Fi"\ 196. bolt head experiment, $1 ; jar for ditto, 2-> cts.,.....l-'£0 285 Fig. 197, Magdeburgh hemispheres, three and a half inch diameter, brass, $4 ; four and a half inch ditto, - 6.00 286 Fig. 197, Magdeburgh hemispheres, three and a half inch diameter, in iron, $4; four and a half inch in ditto, - - - - 5.00 287 Fig. 198, lever and stand for weighing a column of air, ----- 5.00 288 Fig. 199, spouting tube, - - - - 2.50 289 Fig. 200, fountain in vacuo, two sizes, $4.50 and 5.00 290 Fig. 201. expansion fountain, ... 3.50 291 Fig. 202, three globe fountain by elasticity, 2.50 292 Fig. 203, lungs glass, - 2.00 293 Fig. 204, guinea and feather receiver and drops,.......10.00 294 Fig. 205, guinea and feather tube, - $4 and 6.00 295 Fig. 206, bladder and weights, - $1.75 and 2.00 296 Fig. 207, weight lifter by expansion of air, - 5.00 297 Fig. 208, weight lifter with glass cylinder, 3 inch cylinder,.....6.00 298 Fig. 208, weight lifter with glass cylinder, 3^ inch cylinder, - 8.00 299 Fig. 209, large Aveight lifter, with scale board, 4 inch cylinder, ----- 15.00 300 Fig. 210, weight lifter with brass barrel, - 7.50 301 Fig. 210, air shower (used on hand glass), - 0.75 302 Fig. 212, mercury cup " " - 1.00 303 Fig. 213, tube for mercury shower, $4 and 5.00 304 Fig. 214, flask with stop-cock for weighing air, 2.00 305 Fig. 214, " with steel beam and brass stand, 6.00 306 Fig. 215, balance beam and cork ball - - 3.50 307 Fig. 216, receiver with sliding rod, $3.50 and 4.00 308 Fig. 219, " « » bell-shaped, $4 and 5.00 309 Fig. 217, open-top receiver, with plate and sliding rod......5.00 310 Fig. 218, bell in vacuo, 3 sizes, $2.25, $2.50, and 3.00 311 Fig. 219, improved spring bell in vacuo, $2.50 and 3.00 812 Fig. 220, float wheel for showing the resist- ance of the air, - - _ . _ o 75 PNEUMATICS—AIR PUMPS AND APPARATUS. 15 No. 313 Fig. 222, Torricellian experiment with tall re- ceiver, .-__--$ 5.00 314 Fig. 222, Torricellian experiment, with tube to slide, - $3.50 and 4.00 315 Fig. 223, Torricellian experiment used with flexible tube, . - - - - 5.00 316 Fig. 224, water pump in vacuo, with receiver, 8.00 without " 5.00 317 Fig. 225, freezing apparatus, - $1.50 and 2.00 318 Fig. 226, freezing apparatus, with thermo- meter, .....$5 and 7.00 319 Fig. 127, Wollaston's chryophorus in vacuo, with receiver, ----- 5.00 320 Fig. 228, flint and steel in vacuo ; common, 3.50 best, - 5.00 321 Fig. 229, apparatus to fire gunpowder in vacuo, _..--- 4.50 322 Fig. 230, apparatus for showing the effects of burnt air, - 6.00 323 Fig. 230, ditto, tube only, fitting-plate and receiver, Fig. — - - - - - 1.50 324 Cigar tube for smoke in vacuo - - - 0.50 325 Fig. 231, bursting squares, or thin square glass bottles, for breaking by the inward or outward pressure of the air, each, - 0.16 326 Fig. 231, cap and valve for bursting squares, 0.31 327 Fig. 231, wire guard for ditto, - " - - 0.75 328 Fig. 232, transferer with two pint receivers, $8; quart, $10; half gallon, $12 ; gallon, 15.00 329 Single transferer, - - - $3.50 to 6.00 330 Fig. 233, fountain by elasticity, - - - 2.00 331 Fio-. 234, water hammer with stop-cock, - 2.50 332 Fig. 235, water hammer twelve inches long, 75 cts.; twenty-four inches, - 1.50 333 Fig. 236, pressure gauge or indicator, - 12.50 334 Fig. 236, vacuum gauge, - - - - 12.50 16 BENJ. PIKE'S, JR., PRICE CATALOGUE. HYDROSTATICS AND HYDRAULICS. No. 335 Fig. 237, scales and weights in boxes, - $ 1.25 336 Fig. 237, " " «< " fine quality,......3.00 337 Ditto, mounted on a mahogany box with lever stand,.......10.00 338 Sets of grain weights, from T\ of a grain to 1000 grains,......4.00 339 Set of troy weights, from - - $1.50 to 3.00 340 Set of avoirdupois weights, from - - 3.00 341 Fig. 238, hydrometer for spirits, in glass, - 0.75 342 Fig. 238, " " syrups, alkalies, salts, &c.......0.75 343 Fig. 238, hydrometer for heavy acids, - 1.00 344 Fig. 238, alcoholmeter of Guy Lussac, - 1.00 345 Fig, 239, brass hydrometer for spirits, syrups, salts, &c, ---.-. 400 346 Fig. 239, silver hydrometer for spirits, syrups, salts, &c. ------ 6.00 347 Fig. 239, silver alcoholmeter of Guy Lussac, 9.00 348 Fig. 239, brass " « « 6.00 349 Fig. 240, Dica's hydrometer, with thirty-six weights, -.....25.00 350 Fig. 240, Dica's saccharometer with twelve .weights,......25.00 351 Fig. 238, Southworth's silver hydrometer, - 10.00 352 Fig. 241, Nicholson's hydrostatic balance - 3 50 353 Fig. 242, " » « m brass, highly finished, with morocco case, 6.00 354 Fig. 243, Frye's lactometer for testing the purity of milk, - 1 00 355 Lactometer for ascertaining the quantity of cream in milk, - - . . * _ j 50 356 Oleometer for proving the quality of sperm oil, ----... 200 357 Fig. 244, urinometer, - - . . {50 358 Glass jar for urinometer, - 0 50 359 Fig. 245, urinometer in case, with apDaratus, 7.5Q HYDROSTATICS AND HYDRAULICS. 17 No. 360 Fig. 238, Twaddell's hydrometers, from No. 1 to No. 6, each,.....$ 1.75 361 Twaddell's hydrometers, the set of six com- plete in a box, ----- 10.00 362 Fig. 238, hydrometers for vinegar, - $1 to 2.00 363 Fig. 238, hydrometers for salt manufacturers, showing the per centage of salt contained in any brine, ----- 2.00 364 Fig. 238, hydrometers for ascertaining the quantity of salt in steam boilers, at the temperature of 200 degrees, - - - 1.75 365 Fig. 238, brewers' saccharometers, - - 2.00 366 Glass hvdrometer jar, on foot, three sizes, 50 cts.: 75 cts. ; and - - - - 1-00 367 Fio-. 246, tube for showing the relative weight of fluids, ... - 75 cts to 1.50 368 Fig. 247, hydrostatic figure in glass jar, $2.50 to 4.00 369 Fio-. 247, ' " " only, - $1 to 2.00 370 Fig. 248, syphon with drawing tube in glass, 0.75 371 Fio-. 248, syphon with drawing tube in metal, 75 cts. and 1.00 372 Fio-. 248. syphon, plain, in glass, or brass, - 0.38 373 Fi°. 249, Wirtemberg syphon in glass, 38 cts. to 0.75 374 Fig. 250, Tantalus cup, - 2.50 375 Fig. 251, double bodied vessel, - - 1.50 376 Fig. 252, lifting pump with glass cylinder, $3 and 4.50 377 Fio-. 253, forcing pump with brass or glass ■cylinder,.....$5 and 6.00 378 Fio-. 254, forcing and lifting pump in maho- gany frame, - $10 and 12.00 379 Fig. 255, hydrostatic instrument, rise of water to its level,.....- 7-50 380 Fio-. 256, hydrostatic equilibrium, $2.50 and 4.00 381 Fig. 257, " paradox, - - - 3.00 382 Fig. 258, " " 500 383 Fi°. 259, " bellows, $5; extra large, 7.00 384 Fig. 260, vessel for spouting fluids, - - 5.00 385 Fig. 261, Archimedes' screw, - - - 9.00 386 Fig. 262, Barker's mill, - 5.00 387 Fig. 263, centrifugal pump, - 10.00 388 Fio*. 264, Brahma's hydrostatic press, - - 40.00 389 Fig. 265, hydrostatic paradox with movable piston, - 25.00 18 BKNJ. PIKE'S, JR., PRICE CATALOGUE. ELECTRICAL MACHINES AND APPARATUS. No. 390 Fig. 266, Pike's improved plate electrical ma- chines with highly finished brass conductor, insulated on four glass pillars having four rubbers, and two sets of points for collect- ing the fluid, mounted on elegant maho- gany or rosewood frames, Price, with mahogany frame, 24 in. plate, " " " 27 in. " ti a 30 in. tt tt 36 in. t< tt 40 in. tt tt 44 in. rosewood frame, 24 in. a tt 27 in. tt tt 30 in. a tt tt 36 in. 40 in. 44 in. 391. Fig. 267, Pike's improved plate electrical machine, with vertical conductor supported on two glass pillars, with polished mahoga- ny frame. Plate, 13 inches diameter, •i i6 « " 20 " " 392 Fig. 268, Cuthbertson's plate electrical ma- chine, nine inch plate, $7 ; twelve inch plate, $25 ; sixteen inch, $30 ; twenty inch 393 Fig. 269, plate glass electrical machine (French plan), twenty inch plate, 394 Fig. 270, plate glass electrical machine, with positive and negative conductor, brass mounted and highly finished. Plate, 16 inches diameter, $20 and " 20 " " $34 and " 24 " 30 36 42 ft 75.00 85.00 110.00 130.00 165.00 200.00 85.00 95.00 120.00 140.00 180.00 220.00 25.00 30.00 38.00 38.00 50.00 25.00 38.00 50.00 100.00 140.00 200.00 ELECTRICAL MACHINES AND APPARATUS. 19 No. 395 Fig. 271, Nairne's cylinder electrical machine, with positive and negative conductors, ja- panned in imitation of brass, and mounted on glass pillars. Cylinder, 8 in. diameter, $ 22.00 9 in. " 25.00 " 10 in. " 28.00 296 Fig. 272, cylinder electrical machine with highly finished japanned conductor. Cylinder, 5 in. diameter, 10.00 " 6 in. " 12.00 " 7 in. " 14.00 " 8 in. " 16.00 " 9 in. " 18.00 " 10 in. " 22.00 397 Fio-. 273, small cylinder electrical machines. 4 in. diameter, 8.00 5 in. " 10.00 6 in. " 12.00 398 Fig. 274, electrophorus with metal plate, $3.50 to 6.00 399 Fig. 275, electrical insulated stool with ma- hogany top,.....$3 to 6.00 400 Fig. 275, electrical stool, with brass sockets to unscrew, ------ 4.50 401 Fig. 276, Leyden jar, superior finish, pint $1, to $1.25 ; quart, $1.25 ; half gallon, $1.75 ; gallon, ------ $2.50 402 Fig. 277, discharger, with glass handle, - 1-25 403 Fi*. 277, discharger, jointed, with glass handle, - - - - - S2 to 4.00 404 Fig. 278, pith ball electrometer, - - 0.50 405 Fig. 279, " " °'50 406 Fig. 280, balance electrometer, - - - 1.00 407 Fig. 281, quadrant electrometer, boxwood scale, $1.25; ivory, - - - - 1-50 408 Fio- 282, Bennett's gold leaf electrometer, $2 b' and 2.50 409 Fig. 283, Saussure's electroscope, - - 2.00 410 Fig. 284, Volta's condenser, - - - 6.00 411 Fig. 285, Bennett's electrical doubler, - - 5.00 412 Fig. 286, universal discharger, - - $6 to 7.50 413 Fig. 288, medical jar, ... - 2.50 20 BENJ. PIKE'S, JR., PRICE CATALOGUE. No. 414 Fig. 289, discharging or medical electrometer, $ 2.00 415 Fig. 290, Cuthbeitson's balance electrometer, 10.00 416 Fig. 291, electrical battery, four jars, in case, quart, $6.50; four half gallon, $8; four gallon,.......10.00 417 Fig. 291, electrical battery, nine jars, quart, $15 ; half gallon, $18 ; gallon, - - 25.00 418 Fig. 292, electrical battery, fifteen jars, quart $22.50 ; half gallon, $30; gallon, - - 40.00 419 Fig. 293, Leyden jar with movable coatings, 2.00 420 Fig. 293, " " with two sets of mova- ble coatings, - 3.25 421 Glass plate with movable coatings, - - 1.50 422 Fig. 294, magic picture, - - - - 1.75 423 Fig. 295, sulphur cone, - 0.75 424 Fig. 296, electrical bells, set of three bells, 2.00 425 Fig. 297, •« " " two " 1.25 426 Fig. 298, " " " five " 4.00 427 Fig. 299, " " (French arrange- ment), ......4.00 428 Fig. 300, electrical plates for dancing images, 1.25 429 Fig. 301, " " with adjusting rod, 3.50 430 Fig. 302, electrical pith balls, per dozen, - 0.25 431 Fig. 303, glass cylinder with caps for danc- ing pith balls,.....1.50 432 Fig. 304, diverging threads, - - - 0.25 433 Fig. 305, head of hair, - 0.75 434 Fig. 306, image of man or woman with long hair,.....75 cts. and 1.00 435 Tissue paper tassel,.....0.75 436 Fig. 307, radiating feathers, - - - 1.50 437 Fig. 308, electrical swing - 3.00 438 Fig. 309, electrical see-saw, ... 3.00 439 Fig. 310, electrical pendulum, - - - 2.50 440 Fig. 311, electrical spider and jars, - - 2.75 441 Fig. 312, electrical jar, with ball from outside coating, and spider, - - - . 2.50 442 Fig. 313, electrical flyers, - - . 0.50 443 Fig. 314, revolving horsemen on insulated stand, four horsemen, - 2.50 444 Fig. 314, revolving horsemen on insulated stand, six horsemen, - - . . 3 qq ELECTRICAL MACHINES AND APPARATUS. 21 No. 445 Fig. 315, electrical flyers, set of five on one frame,......$ 4.50 446 Fig. 316, electrical orrery, sun, earth, and moon, revolving, ----- 2.50 447 Fig. 317, electrical inclined plane, - - 3.00 448 Fig. 318, sportsman, and Leyden jar, - - 3.00 449 Fig. 318, sportsman only, - - - 1.75 450 Fig. 319, electrical rope dancer, - - 2.00 451 Fig. 320, electrical swan, - - - - 0.50 452 Fig. 321, rolling glass balls, - - - 5.00 453 Fig. 322, electrical bucket and syphon, 75cts. and 1.00 454 Fig. 323, phosphorus cup, - - - 3.50 455 Fig. 324, electrical wheel, - - - 5.00 456 Fig. 325, electrical saw mill - 6.00 457 Fig. 226, rotating bell glass, - - - 4.00 458 Fig. 327, electrical vane, - - - $1 to 2.00 459 Fig. 328, electrical wind mill, - - - 5.00 460 Fig. 329, electrical cross, - - - - 2.50 461 Fig. 330, spiral and flyer, - 3.00 462 Fig. 331, revolving glass globe, - - - 2.50 463 Fig. 332, aurora tube, twenty inch, $4.50 ; thirty inch, $6 ; thirty-six inch, - $7 to 10.00 464 Fig. 333, aurora flask, ... - 2.50 465 Fig. 334, luminous discharger, - - - 2.00 466 Fig. 335, spiral tube, 16 inch, $2; 20 inch, 2.50 " 30 to 48 inch, $3 to 5.00 467 Fig. 336, set of spiral tubes on stand, with revolving balls, - -. - - - 10.00 468 Fig. 337, luminous word, in frame, - - 3.00 469 Fig. 338, luminous crescent, - - - 3.00 470 Fiff. 339, spotted or diamond jar, pint, - 2.00 & « " « quart, - 3.00 471 Fig. 340, egg stand, - - - $1 and 2.00 472 Fig. 341, electrical fire-house, - - - 4-00 473 Fig. 342, electrical belted bottle, - - 3.00 474 Fig. 343, electrical cannon, - - - 2-00 475 Fig. 344, electrical mortar, - - - - 3.00 476 Fig. 345, electrical pistol, - - $2 and 3.00 777 Fig. 346, apparatus for firing gunpowder by electric spark,.....3-50 478 Fig. 347, apparatus for firing spirits of wine, ether, <'-ml......2.00 BENJ. PIKE'S, JR., PRICE CATALOGUE. 35 No. 789 Fig. 559, Marcett's steam boiler with barome- ter and thermometer, for experiments on latent heat, &c, - - - - - $ 15.00 790 Fig. 560, Wollaston's steam apparatus, - 1.50 791 Fig. 561, calorimeter, - 792 Fig. 562, pair of tin plate mirrors for radia- tion of heat, with stands, 12 inch diameter, 5.50 793 Fig. 562, ditto, with iron ball and differential thermometer, with stands, - 7.50 794 Fig. 562, ditto, in brass, thirteen inch, $20; eighteen inch, ----- 32.00 795 Square box with four different radiating sur- faces, ------- 1.50 796 Fig. 563, still and worm of japanned tin, - 6.00 797 Fig. 563, " " of copper, - - 8.00 798 Fig. 564, Hope's eudiometer, - - - 2.50 799 Volta's eudiometer, with platina poles, - 3.00 800 " " and graduated, 4.00 801 Fig. 565, Ure's " " " 4.00 802 Fig. 566, Pepy's gas transferrer - - 0.75 803 Fig. 567, glass syringe for transferring, - 0.75 804 Fig. 568, apparatus to show the condensation of liquids by mixture - - - $1 to 3.00 805 Fig. 569, tube and flask holder, - - 1.50 806 Fig. 570, apparatus for distillation and con- densation of liquids, with 3 retort stands, 6.00 807 Fig. 571, apparatus for the condensation of gases, with a retort stand, - 3.50 808 Fig. 572, Wolf's apparatus, in tray, $6, $6.50, and 7.50 809 Fig. 572, Bent tubes for Wolf's apparatus, 25cts. to 0.38 810 Fig. 572, Wolf's three-necked bottles, half- pint, 63 cts; pint, 75cts; quart, - - 1-00 811 Fig. 573, Nooth's apparatus, - - - 15.00 812 Fio- 574, Christison's apparatus for detecting poisons, - - - - $.400 and 5.00 813 Fig. 575, Marsh's arsenic apparatus, - 2.50 814 Fig. 576, retort, with cap and stopcock, - 1.50 815 Specific gravity bottle to hold 1000 grains of water,....." " 3-00 816 Fio-. 477, glass-blower's table, with double bellows, ------ 25.00 36 METEOROLOGY. 817 Fig. 578, apparatus for chemical analysis, - $ 2.50 8J98f|«o: " •»■*>"* »»-«j 820 Fig. 581, one-bulb tube, - - 0.6b 821 Fig. 582, two-bulb tube, - °-50 822 Fig. 583, five-bulb potash apparatus, - - 1.25 823 Fig. 584, drying tube, ... - 0.37 824 Fig. 585, drying tube, - 0.75 825 Bottles with glass stoppers, 2 ounces, 14cts.; gill, 16cts.; half-pint, 18cts.; pints, 20cts.; quarts, ------ 0.25 826 Bottles with wide mouths and glass stoppers, two ounces, 15cts. ; gill, 18cts. ; half-pint, 25cts. ; pint, 31cts. ; quart, 38cts; half- gallon, ------ 0.56 METEOROLOGY. 827 Fig. 586, thermometers in japanned tin case, 6 inch, 0.63 " " 7 inch, 0.75 " " 8 inch, 0.87 " " 10 inch, 1.00 « " 12 inch, 1.25 14 inch, 1.50 With Reaumur or centigrade scale, 25cts. to 50cts. extra. 828 Fig. 587, thermometers, with mahogany backs (Pike's improved), - 8 inch, 1.00 " 10 inch, 1.25 " " 12 inch, 1.5Q «• " 14 inch, 1.75 829 Fig. 587, ditto, fourteen inch, with Fahrenheit and centigrade scale, and movable index, - 2.50 830 Fig. 588, ornamental mahogany frame ther- mometer, - - - - 12 inch, 1.75 " " 18 inch, 2.50 " " 24 inch, 6.00 BENJ. PIKE'S, JR., PRICE CATALOGUE. 37 No. 831 Fig. 589, mahogany frame thermometer, with glass in front, with flat glass, 12 inch, $ 1.75 " " " ' 14 inch, 2.00 " " " 20 inch, 5.00 with circular glass, 12 inch, 2.25 " 14 inch, 2.50 " 20 inch, 6.00 832 Fig. 590, thermometer in morocco case, 8 in., 1.50 833 Fig. 590, " " " with Fahrenheit and Reaumur scale, - - 1.75 834 Fig. 590, thermometer in morocco case, three to six inch, - - - - $1.25 to 1.50 835 Fig. 590, thermometer in morocco case, three to six inch, ivory scale, - $1.50 to 2.00 836 Fio-. 592, self-registering thermometer for day, or extreme heat, ----- 2.50 837 Fig. 592, self-registering thermometer, for night, or extreme cold, - - - - 2.00 838 Fig. 591, self-registering thermometer, for day and night, in one frame, - - - 4.00 839 Ditto, with improved cylinder bulbs, - - 5.00 840 Fig. 592, self-registering thermometer for ex- treme heat, with index, extra large size, - 3.00 841 Fig. 592, ditto, for extreme cold, - - 3.00 842 Fig-. 586, thermometers for sea use, in copper 5caseSi ----- $1.25 to 2.00 843 Fig. 586, thermometers for low temperatures, with alcohol in tube, - - - - 2.00 844 Thermometers with delicate tubes and small light scales for chemical experiments, 75c. to 1.00 845 Chemical thermometer to 400 deg., 10 inch, 1.50 400 " 12 " 1.75 400 " 14 " 2.00 600 " 14 " 3.00 846 Chemical jointed thermometer to 400 deg., fourteen inch, - - - " 847 Chemical jointed thermometer to 600 deg., fourteen inch, - " «48 Wollaston's barometrical thermometer, with copper boiler, - - ■ 849 Medical thermometers, - - - *i to o.uu 850 itory steeple « highly ornamented, $6 to 15.00 38 METEOROLOGY. No. 851 Fig. 593, thermometers for sugar boiling, ma- hogany frame, three feet, - - - $ 4.00 852 Fig. 593, thermometers for sugar boiling, with index, three feet, - 4.50 853 Fig. 593, thermometers for sugar boiling, ma- hogany frame, four feet, - 5.00 854 Fig. 593, thermometers for sugar boiling, with index, four feet, - 6.00 855 Fig. 594, thermometers for sugar boiling, brass case, three feet, _ - - - 5.50 856 Fig. 594. thermometers for sugar boiling, brass case, four feet, - 7.00 857 Figs. 595 to 603, thermometers for mantel, Gothic frames, over twenty-five different patterns, from - - - - $1 to 2.50 858 Fig. 604, pediment barometer with thermo- meter, plain mounting, - - - - 10.00 859 Fig. 605, pediment barometer with thermo- meter and glass door, - - $11 and 12.00 860 Fig. 606, ditto, with large thermometer, - 16.00 861 Fig. 607, ditto, with best circular front, $20 to 25.00 862 Fig. 608, mountain barometer in small round case, ------ . 20.00 863 Fig. 608, mountain barometer with corrections, 25.00 864 Fig. 608, Pike's mountain barometer for aca- demies, &c, ... - $10 and 12.00 865 Fig. 609, Pike's standard barometer, - - 22.00 866 Fig. 610, marine barometer on gimbals, $20 to 25.00 867 Fig. 611, Troughton's mountain barometer, with brass frame and portable folding staves and gimbals, ----- 45.00 868 Fig. 612, wheel barometer, mahogany frame, dial, eight inch, $12 ; ten inch, - - 15.00 869 Fig. 612, wheel barometer, rosewood frame, eight inch, $15; ten inch, $18; twelve .mch, - -.....25.00 870 Fig. 612, wheel barometer, with rosewood case inlaid with pearl, - 25.00 871 Fig. 613, prognosticated, or storm-glass, - 1.25 872 Fig. 614, differential thermometer, on stand 1 50 873 Fig. 615, Howard's » « {50 BENJ. PIKE'S, JR., PRICE CATALOGUE. 39 No. 874 Fig. 616, hygrometer for showing the dryness or moisture in the air, &c. - - $ 2.50 875 Fig. 617, Saussure's hygrometer, - - 5.00 876 Fig. 618, Daniell's " - - 14.00 877 Fig. 619, Mason's " - $3.50 to 5.00 878 Fig. 619, ditto, stand, packed in rosewood case, 7.00 879 Fig. 620, Jones's hygrometer, - - - 5.00 880 Fig. 621, Leslie's thermometric hygrometer, - 5.00 881 Fig. 622. conical rain gauge, - - - 2.50 882 Fig. 623, cylindrical rain gauge, with gradu- ated tube, - - - - . 7.50 883 Fig. 623, '• " with float, - 6.00 884 Fig. 624, Lind's wind gauge, - - $6 to 8.00 885 Fig. 625, Cumming's statical thermometer, - 25.00 SPECTACLES, EYE-GLASSES, &c. 886 Figs. 628 and 632, gold spectacles, with single joints, octagon, oblong, or oval eye, $7 and S.00 887 Figs. 629 and 632, ditto, extra fine, - 9 and 10.00 888 Figs. 630 and 631, gold spectacles, double jointed, with slide or turnpin, $8 and 9.00 889 Figs. 630 and Fig. 631, ditto, extra fine, $10 to 13.00 Best pebble eyes, extra, for concave, - 2.50 " " for convex, - 1.75 890 Figs. 629 and 632, silver spectacles, single jointed, $2.00; extra, - - - - 2.25 891 Fio-s. 630 and 631, silver spectacles, double iointed, with slide or turnpin, - - - 2.00 J «« " extra, $2.25 to 2.50 892 Fig. 635, steel spectacles, blued, of fine quality, single joints, very elastic and light, with octagon, oblong, or oval eyes, $2 to 2 50 893 Fio-. 635, ditto, of good quality, $1.25 and 1.50 894 " inferior, - 62cts. to 1.00 895 Figs. 633 and 634, steel spectacles, blued, of fine quality, very elastic and light, double ioints, with oval, oblong, or octagon eyes, J $2.50 and 3.00 40 SPECTACLES, EYE-GLASSES, ETC. 896 Fig. 634, steel spectacles, good quality, $1.25 and $1.50 897 Fig. 634, ditto, of inferior quality, 75cts. and 1 00 898 Steel spectacles, stout, highly polished, oval eyes, turnpin on sliding bows, best quality glasses, 75cts.; inferior, - 0-38 899 & 900 Fig. 636, tortoise-shell spectacles, very light, single jointed, $2; double, - 3.00 901 Tortoise-shell spectacles, silver sides, $2.50 to 3.50 902 Gilt, and gilt on silver spectacles, $2 to 3.00 903 German silver spectacles - - 50cts. to 1.00 904 Horn-mounted " - - 75cts. to 1.25 905 Fig. 637, spectacles for reading and public speaking, in fine steel, silver, or gold mounting, ... - $1.50 to 10.00 906 Spectacles for eyes that have been couched, $1 to 3.00 907 Fig. 638, spectacles with folding side glasses, of blue or neutral tint, for weak or in- flamed eyes, in fine elastic steel, $4.50 and 5.00 908 Ditto, of ordinary quality, - - $1.50 to 2.50 909 Ditto, with silver mounting, - $3 to 6.00 All the above are set with best concave or convex, blue, neutral tint, or green glasses, and a morocco case included. Spectacles, with blue or green convex glasses, extra, ------ 0.25 " with blue or green concave glasses, extra, 0.50 " with truly ground periscopic glasses, extra, - 0.50 " with best Brazil pebbles, convex, extra, 1.75 " " concave, " 2.50 " with divided glasses for two sights, extra,.....0.50 910 Fig. 639, morocco spectacle cases, fine quality, 0.12 911 Fig. 639, " « « ordinary, 0.10 912 " " " long, for ladies' spectacles, - - - - . 0.12 913 Spectacle cases in tortoise shell, silver mount- on o ed* , " •" „ " " • $2.50 to 4.50 914 bpt-ctacle cases in German silver, 50 cts. to 0 75 915 " " in steel, - q'oo 916 Fig. 640, eye glasses, in black horn mounting round, ----- °: o.63 BENJ. PIKE'S, JR., PRICE CATALOGUE. 41 No. 917 Fig. 641, eye glasses in black horn mounting, square, _...--$ 0.63 918 Fig. 642, eye glasses, in tortoise shell mount- ing, .......1.00 919 Eye glasses, in silver mounting, - - $1 to 1.25 920 Fig. 642, eyeglasses, in fine steel mounting, $1 to 1.25 921 Fig. 643, " " in gold plated " $2 to 3.00 922 Fig. 644, " " " " " $3 to 5.00 923 " " in solid gold " 5.00 924 Fig. 645, reader, in gold, plated large size,.....$4 to 5.00 925 Fig. 646, eye glasses for both eyes, in black horn mounting, - - - - - 1-25 926 Fig. 646, eye glasses for both eyes, in tortoise- shell mounting, ----- 1.75 927 Fig. 647, eye glasses for both eyes, in fine steel mounting, - - - - - 2.25 928 Fig. 647, eye glasses for both eyes, in silver mounting, ------ 2.00 929 Fig. 648, eye glasses for both eyes, in gold plated mounting, - - - - $5 to 7.00 930 Fig. 648, eye glasses for both eyes, in gold plated mounting, with spring, - $5 to 15.00 931 Fig. 647, eye glasses for both eyes, in solid gold,.....$6.50 to 10.00 932 Fig. 649, folding eye glasses, folding into pearl or shell cases, - - $3, $4, and 5.00 933 Fiff. 650, reading glasses, hom mounted, $1, & $1.50, and 2.00 934 Fig. 651, reading glasses in pearl and silver mounting, - - - - - $8 to 10.00 935 Fig. 652, videscope, a large, magnificent lens, mounted with sliding tubes, clamp, &c, to screw to the table for reading, drawing, &c.....$5 and 5.50 936 Fig. 653, goggles to guard the eye from wind and dust, - - - 75cts. to 1.25 937 Fio- 654, goggles, or eye protectors, of wire gauze, - - . ." - $1 and 1.25 938 Fig. 655, goggles for squinting, - - 0.88 939 Fig. 656, " improved, - 1.50 940 Fig. 657, magnifiers, in black horn mounting, 0.44 42 TELESCOPES, ETC. 941 Fig. 658, magnifiers, in black horn mounting, larger, $ 0.50 942 Fig. 659, 943 Fig. 660, 944 Fig. 660, 945 Fig. 661, 946 Fig. 661, 947 Fig. 662, 948 Fig. 662, " for burning. &c. 0.75 bellows-shaped, 1 lens, 0.63 " 1 lens, larger, 0.75 2 " - 1.00 " 2 " larger, 1.25 " 3 " - 1.38 " 3 " larger, 1.50 949 Fig. 663, watch-maker's magnifier, in black horn,.......0.38 950 Fig. 664, engraver's eye glass, in black horn, 62cts. and 0.75 951 Fig. 665, " in cocoa wood, large, 1.00 952 Fig. 665, " « extra, 1.75 953 Fig. 666, " with two lenses, in me- tal cases, $1.50 to 1.75 954 Fig. 666, " with two periscopic lenses, improved, 1.75 955 Fig. 667, hand magnifier, in metal rim and long handle, ... _ - . o.75 956 Fig. 668, hand microscope, or doublet, with two lenses,......1.00 957 Fig. 669, " " larger, 75cts. and 1.00 958 Fig. 670, Stanhope lens, - 2.00 959 Fig. 671, linen and cloth prover, in wood box, 0.62 960 Fig. 671, " « brass, - 0.75 961 Fig. 672, " " " extra finish, 0.88 962 Fig. 673, " « with slide head, 1.00 963 Fig. 674, " « folding in brass, 0.75 964 Fig. ,674, " « best finish » 1.25 965 Fig. 674, " « German silver, 1.50 966 Fig. 675, woollen provers, of large size, $1.50 to 2.00 TELESCOPES, &c. 967 Opera glasses, single, in plated or gilt mount- ing, - - - - . -$lto2 00 968 Opera glasses, single, extra, - - $4 to 8.00 BENJ. PIKE's, JR., PRICE CATALOGUE. 43 9<59 Fig. 675, opera glasses, double, for both eyes, ordinary,.....$3 to $ 4.00 970 Fig. 676, opera glasses, double, for both eyes, good quality, - - - $3.50 to 5.00 971 Fig. 677, opera glasses, double, with superior achromatic lenses, in ivory mounting, $6 to 12.00 972 Fig. 678, opera glasses, double, with superior achromatic lenses, in black mounting, $7 to 15.00 973 Fig. 678, opera glasses, double, with superior achromatic lenses, in tortoise-shell mount- ing, ......$15 to 22.00 974 Fig. 679, Galilean telescopes, one draw, 50c, extra large, ------ 1.00 975 Fig. 679, Galilean telescopes, two draw, 75c, extra large, ------ 1.25 976 Fig. 680, Galilean telescopes, three draw, $1, extra large, - - ■ - - - - 1.50 977 Fig. 681, pocket achromatic telescopes, six- teen inch, three draw, - - - $5 to 6.00 978 Fig. 681, pocket achromatic telescopes, twen- ty-two inch, three draw, ... 8.00 979 Fig. 681, pocket achromatic telescopes, thirty inch, three draw,.....12.00 980 Fig. 682, pocket achromatic military tele- scopes, fifteen inch, six draw, $7.50 to 10.00 981 Fig. 682, pocket achromatic military tele- scopes, twenty inch, six draw, - - 10.00 982 Fig. 682, pocket achromatic military tele- scopes, twenty-four inch, six draw, $12 to 15.00 983 Fio-. 682, pocket achromatic military tele- scopes, thirty inch, five draw, - $14 to 16.00 984 Fio-. 682, pocket achromatic military tele- scopes, thirty inch, four draw, - $12 to 20.00 985 Fig. 683, ditto, ditto, the above with sun shade, extra, - - - 50 cts. to 1.50 986 Leather case for military telescopes, $2 to 4.00 987 Fig. 685, achromatic ship telescope, best glasses, with one, two, or three, brass slid- ing tubes and sun shade, - $9 and 10.00 988 Achromatic ship telescope, with leather body, $11 to 13.00 989 Fio-. 685, ship telescopes with common glasses, 7.00 990 Telescopes, extra large and extra power, $22 to 25.00 44 LENSES, ETC. LENSES, &c. No. 991 Fig. 686, plane glass, If diameter, - $ 0.12 992 Fig. 687, double convex lens, - 0-38 993 Fig. 688, double concave " " 38cts. to 0.62 994 Fig. 689, plano-convex " " 50cts. to 0.62 995 Fig. 690, plano-concave " " 50cts. to 0.62 996 Fig. 691, meniscus " " - 0.50 997 Set of lenses for showing their form and pro- perties ; consisting of double convex, double concave, plano-convex, plano-concave, me- niscus or concave-convex, and plain glass, all with ground edges, 1 f inch diameter, - 1.50 Set of four first, 2 inches diameter, - - 3.50 « 3 - - 6.00 998 Cosmorama lenses, convex, 7 inch diameter, 2.50 999 " " 6 inch " 1.75 1000 " " 5 inch " 1.25 1001 " " 4 inch " 1.00 1002 " " 3 inch " 0.75 1003 Magic lantern lenses, the pair, 2 inch, 1.25 1004 " " 2i inch, 1.75 1005 " • " 3 inch, 4.00 1006 " " 3| inch, 5.50 1007 " " 4 inch, 6.50 1008 Microscope lenses, double convex, one inch focus and upwards, £ inch diameter, - 0.38 1009 Microscope lenses, double convex, half inch focus, 50cts. ; quarter inch focus, 63cts.; one eighth inch focus, - 0.88 1010 Microscope lenses, plano-convex, one inch, 50cts. ; three quarter inch, 63cts; half- inch, 75cts.; quarter inch, ... 0.88 1011 Microscope lenses, diameter, li_ inches, 38cts. to 1.00 1012 Telescope lenses, for eye-glasses, 38cts. to 0.50 1013 " for object, 25cts. to 1.00 1014 " " superior, 6 ft. focus, 1.25 1015 concave, for Gregorian eye- glass, - 38cts. to 0.50 1016 " achromatic, 18 inch, - 2.50 to 42 inch, - - 25.00 BENJ. PIKE'S, JR., PRICE CATALOGUE. 45 No. 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 Daguerreotype lenses, from - $1.25 to " achromatic, $2 to Set of three lenses for compound microscope condenser, 1£ inch diameter, Set of two lenses for solar microscope con- denser, 2 inch diameter, " " for telescope, 6 ft. focus, Camera obscura lenses, 25cts.; and larger, to Fig. 692, model of double convex lens with converging rays, - - - - Fig. 693, model of plano-convex lens with converging rays, - - - - - $2.00 8.00 1.25 1.12 1.37 2.00 1.75 1.50 1.00 LOP 1028 1029 1030 1031 1032 Diminishing 1033 " 1034 1035 1036 Cylindrical 1037 1038 1039 Mirrors with nine faces, 1040 Grotesque mirrors, - MIRRORS. s, 8 inches <] 6 it 5 u 4 « 3 1< 6 « 5 « 4 << 3 << 6 (( 5 << 4 a 5.00 1.75 1.00 0.63 0.50 2.00 1.25 0.88 0.75 2.00 1.50 1.12 to 3.00 to 5.00 OPTICAL INSTRUMENTS. 1041 Fig. 694, model of the eye, 1042 Fi"-. 695, image on the retina, 5.00 2.50 46 OPTICAL INSTRUMENTS. No. 1043 Fig. 696, instrument for showing the nature of vision,......$ 6-00 1044 Fig. 697, muscles of the eye, - - - 2.50 1045 Figs. 694 to 697, set of the above four in- struments, ------ 13.00 1046 Figs. 694, 696, and 697, set of the first, third, and fourth,.....11.00 1047 Fig. 698, prisms, 37 cts., $1, $1.50, $2, and 3.00 1048 Fig. 698, prisms, mounted, - - $2 to 5.00 1049 Compound prisms of three different kinds of glass, each having a different refractive power,......3.00 1050 Fig. 699, instrument for the recomposition of light,.......1.00 1051 Fig. 700, glass box for experiments on re- fraction, - - - _ $4 and 5.50 1052 Fig. 701, optical diagonal machine, four inch, ----- $1.75 and 2.50 1053 Fig. 701, optical diagonal machine, five inch,.....$2.25 and 2.50 1054 Fig. 701, optical diagonal machine, six inch, ----- $2.75 and 3.00 1055 Prints for diagonal machine, fourteen inch by twenty-two inch, per dozen, - - 1.00 1056 Fig. 702, portable camera obscura, $2.50, $3.50, and 6.00 1057 Fig. 703, camera obscura for draughtsmen, 8.00 1058 Fig. 704, Daguerreotype apparatus, rose- wood camera with German arrangement of achromatic lenses, mounted in brass tubes, with rack and pinion motion, - - - 25.00 1059 Stand for camera, - - - - $3 to 5.00 1060 Two coating boxes, per pair, .... 4.50 1061 Mercury box of cast iron, on foot, - - 1.50 1062 Plate vice, for holding the plates while cleaning,......j 75 1063 Buff sticks, ----.. q.25 1064 Thermometer for mercury box, - - - 0^38 1065 Glass spirit lamp, - - - 20 cts. to 0.75 1066 Head rest to fasten to chair, - 3.00 1067 Daguerreotype plates, medium size, $3 doz. quarter size, ----- 450 BENJ. PIKE'S, JR., PRICE CATALOGUE. 47 No. 1068 Fig. 706, camera lucida, - - - $8 to $12.00 1069 Fig. 707, graphic mirror, - - $10 to 12.00 1070 Fig. 708, polemoscope, - 5.00 1071 Multiplying glass, - 50 cts. to 3.00 1072 Fig. 709, Claude Lorraine glass, with four to six glasses, - - - - $1.50 to 3.00 1073 Claude black glass mirrors, ... 2.50 POLARIZATION OF LIGHT. 1074 Fig. 711, prism for double refraction, $2.50, $4, and 5.00 1075 Nichol's prism,.....5.00 1076 Tourmaline plates, - - - $2 to 6.00 1077 Fig. 712, tourmaline polariscope, - $4 and 4.50 1078 Variety of crystals set in cork frames between glass plates, for preservation, used with the polariscope, each - - - 0.75 1079 Figs. 717 to 722, selenite designs, in polished mahogany frames, - - each $2.50 to 4.00 1080 Fio-. 723, Biot's reflecting polariscope, - 36.00 1081 Fig. 724, polariscope, with six selenite de- signs in case, ----- 25.00 1082 Fio-. 725, brass frame, for showing the tran- sfent polarizing structure communicated by pressure to a piece of annealed glass, - 3.50 1083 Fig. 728, brass frame for showing the same by the unequal application of heat, - 2.00 1084 Fig. 726, brass frame and glass plate for showing the same by bending, - - 5.00 1085 Fig. 729, five unannealed glasses for show- ing the tints of polarized light, - - 8.00 1086 Ten ditto,......15-00 1087 Two rectangular pieces of unannealed glass, which may be placed over or across each other, for showing the tints of polarized light, --.---- 25° 1088 Savarre polarizing eye-piece, - - 6.00 48 MAGIC LANTERNS AND SLIDERS. MAGIC LANTERNS AND SLIDERS. No. 1089 Fig. 731, magic lantern, with oil lamp and reflector, and 12 slides, in mahogany frames and box, - - lens 2 inch diameter, $ 5.50 1090 Fig. 731, " 1\ " 8.00 1091 Fig. 731, " 3i " 10.50 1092 German magic lantern slides with paper edges, - - - 75cts., $1.00, and 1.50 1093 Fig. 732, phantasmagoria lanterns, lenses 4 to 41 inch diameter, - 15.00 1094 Fig. 733, improved phantasmagoria lanterns, lenses 3 inch diameter, with spring to hold sliders, brass adjusting tubes, and solar lamp, 14.00 1095 Fig. 733, " Jenses 34. inch diameter, 15.00 1096 Fig. 733, " " 4 " 18.00 1097 Fig. 736, pair of improved lanterns for dis- solving views, ----- 50.00 1098 Magic lantern sliders, comic and amusing subjects, in great variety, sliders, 1\ inch wide, 9 in. long, with 4 or 5 views, per doz. 4.50 1099 Ditto, sliders 3 in. wide, 12 in. long, per doz. 9.00 1100 " 4 " 15 " 5 views, 15.00 1101 Fig. 737, movable comic sliders, representing a great variety of amusing changes, by drawing the loose slide, a few of which are enumerated, viz. Blooming of carnation pink, " rose, Bleeding nun, Death on the pale horse, Chrysalis worm and butterfly, Mount Vesuvius and eruption, Tight-rope dancing, Fencing, Moss rose blooms, and exhi- bits Cupid, Tailor and goose, Boy and beer barrel, Turk's head and eyes to move, Blacksmith at work, Tailor " Barber " Shoemaker " Ship firing, " in storm, Jim Crow, Winter and summer, Old man and death, Dragon and movable wings, Sailor and dance, Trying to get through the world, And a great variety of others, too numerous to mention Price, 3 in. wide, each, 83cts.; 4 in., $1.25. BENJ. PIKE'S, JR., PRICE CATALOGUE. 49 No. 1102 Dioramic sliders, beautiful views, with mov- ing objects, shipping, &c. each, 1103 Dioramic views of City Hall, Astor House, Trinity Church, Custom House, &c, with passengers, &c. - - - - - Set of astronomical sliders, 11 slides, three of which are movable, containing 32 diagrams, viz. $ 2.50 4.00 1 Rotundity of the earth (movable), 2 System of Ptolemy, 3 " Copernicus, 4 " Tycho Brahe, 5 " Newton, 6 Telescopic view of the Moon, 7 * " Jupiter, 8 " " Saturn, 9 Comparative sizes of the planets, 10 Comparative distances of the planets, 11 Orbit of a comet, 12 Comet of 1811, 13 Signs of the zodiac, 14 Inclination of the planets' orbits, 15 Direct and retrograde mo- tion, 16 The seasons, 17 Phases of the moon, 18 The earth's shadow, 19 Ditto, 20 Ditto, 21 Cause of the moon's eclipse, 22 Cause of the sun's eclipse, 23 Inclination of the moon's orbit, 24 Eclipse of sun (movable), 25 " moon " 26 Spring tide at new moon, 27 " at full moon, 28 Neap tide, 29 The constellation Ursa Major, 30 The constellation Orion, 31 Portion of the milky way 32 Various nebulae, 1104 Fig. 740, 3 sizes, 1105 Fig. 740, 1106 Fig. 740, largest 9 in. long, 21 in. wide, $ 7.50 12 " 3 " 15.00 15 « 4 " 20.00 50 MOVABLE ASTRONOMICAL DIAGRAMS. MOVABLE ASTRONOMICAL DIAGRAMS, THE MOTION PRODUCED BY RACK-WORK. No. 1107 No. 1, the solar system, showing the revo- lution of all the planets with their satel- lites round the sun, ... - $ 5.75 1108 No. 2, the earth's annual motion round the sun, showing the parallelism of its axis, thereby producing the seasons, - - 5.00 1109 No. 3, this diagram illustrates the cause of spring and neap tides, and shows the moon's phases, during its revolution, - - - 4.25 1110 No. 4, this diagram illustrates the apparent direct and retrograde motion of Venus or Mercury, and also its stationary appearance, 4.00 1111 No. 5, a diagram to prove the earth's rotun- dity, -......3.75 1112 No. 6, this diagram illustrates the eccentric revolution of a comet round the sun, and shows the appearance of its tail at different points of its orbit, - 5.25 1113 No. 7, The diurnal motion of the earth, showing the rising and setting of the sun, illustrating the cause of day and night, by the earth's rotation upon its own axis. - 4.00 1114 No. 8, this diagram illustrates the annual motion of the earth round the sun, with the monthly lunations of the moon. - 5.75 1115 No. 9, this diagram shows the various eclips- es of the sun with the transit of Venus, 4.00 1116 Or the whole set in a box with lock and key, 38.00 1117 Constellations in six sliders; their situation with regard to the north pole is denoted by an arrow. Slider No. 1.—1, Aries ; 2, Taurus ; 3, Ge- mini ; 4, Cancer. Slider No. 2.-5, Leo; 6, Virgo ; 7, Libra; 8, Scorpio. BENJ. PIKE'S, JR., PRICE CATALOGUE. 51 No. Slider No. 3.—9, Sagittarius ; 10, Capricor- nus ; 11, Aquarius ; 12, Pisces. Slider No. 4.—13, Draco and Ursa Minor ; 14, Cepheus and Cassiopeia; 15, Andro- meda and Triangula ; 16, Auriga. Slider No. 5.—17, Perseus and Caput Medu- sae ; 18, Bootes and Canes Venatici; 19, Hercules and Cerberus ; 20, Cygnus and Lyra. Slider No. 6.—21, Antinous and Aquila; 22, Ophiuchus and Serpens ; 23, Canis Ma- jor and Minor; 24, Cetus. $12.00 1118 Set of five slides, illustrating water spouts, from Dr. Lardner's lectures, the set, - 10.00 1119 Set of six slides, illustrating auroras, from Dr. Lardner's lectures, the set, - - 12.00 1120 Fig. 741, natural history sliders, in sets of twelve slides, three sizes;— 9 inches long, 2| wide, containing 36 views, 5.00 1121 12 " 3 " " 36 " 12.50 1122 15 " 4 " " 60 " 20.00 1123 Figs. 741 and 742, set of natural history sliders, in fifty-six slides, and over 200 diagrams, of which twenty-four sliders are mammalia, seven birds, four amphibia, five fishes, eight insects, eight worms, with book explaining the whole, - - - - 100 00 1124 Separate sliders, each, - - - - 2.00 1125 Fig. 743, costumes of all nations, in twelve sliders, forty-eight views large size, - - 20.00 1126 Fig. 743, modern costumes of nations, fifty- six sliders, containing above 290 figures— viz. 4 England, 3 France, 5 Austria, 1 Iceland, 4 Russia, Greenland, and Lapland, 3 Turkey, 4 Tartary and Circassia, 4 China, 3 Persia and Arabia, 3 Empire of Cabul, 1 Birman Empire, 5 Hindostan, 2 Greece, 3 Java and Asiatic Islands, 3 Egypt and Abyssinia, 4 Tripoli and North Africa, 4 South Sea Islands and northwest coast of America, ------ 100.00 52 SCRIPTURE DIAGRAMS. No. 1127 Ancient Costumes in six sliders, and twenty- five figures, - - - - " - $ 12.00 1128 Fig. 744, Scripture history sliders, in twelve slides, viz.:— Slider No. 1.—Adam and Eve driven out of Paradise, Gen. c. 3, v. 24; Hagar and Ishmael, Gen. c. 21, v. 14; Isaac blessing Jacob, Gen. c. 27, v. 23. Slider No. 2.—Joseph sold into Egypt, Gen. c. 37, v. 28; Joseph meeting his father, Gen. c. 50, v. 1; the finding of Moses, Exod. c. 2, v. 5. Slider No. 3.—The ark of the covenant, Exod. c. 25, v. 10; the dress of the high priest, Exod. c. 28, v. 2; the altar of in- cense, Exod. c. 30, v. 1. Slider No. 4.—The altar of burnt offering, Exod. c. 27, v. 1 ; an Aaronite or scribe, Exod. c. 28, v. 40 ; the golden candlestick, Exod. c. 25, v. 31. Slider No. 5.—Return of the spies, Num. c. 13, v. 23; the brazen serpent, Num. c. 21, v. 9; Balaam and his ass, Num. c. 22, v. 22. Slider No. 6.—Samson and the lion, Judges c. 14, v. 6 ; presentation of Samuel, 1st Sam. c. 1, v. 28 ; Samuel in the temple, 1st Sam. c. 3, v. 10 ; Elijah fed by ravens, 1st Kings, c. 17, v 6. Slider No. 7.—David and Goliath, 1st Sam. c. 17, v. 51 ; David dancing before the ark, 2d Sam. c 6, v. 14; Nathan reprov- ing David, 2d Sam. c 12, v. 7. Slider No. 8.—The annunciation, Luke, c. 1, v. 28; the birth of Christ, Luke, c. 2, v. 16 ; Christ brought to the temple, Luke, c. 2, v. 22. Slider No. 9.—The flight into Egypt, Matt. c. 2, v. 13; the holy family, Mark, c. 1 ; Christ and the woman of Samaria, John c' 4, v. 7. BENJ. PIKE S, JR., PRICE CATALOGUE. Slider No. 10.—Christ stilling the tempest, Matt. c. 8, v. 24; the good Samaritan, Luke, c. 10, v. 30 ; the lord of the vine- yard and laborer, Matt. c. 20, v. 12. Slider No. 11.—The return of the prodigal son, Luke, c. 15, v. 20; trial of Peter's faith, Matt. c. 14, v. 29 ; Herodias with the head of John the Baptist, Mark, c. 6, v. 28. Slider No. 12.—The crucifixion, John, c. 19, v. 30; the women at the sepulchre, Mark c. 16, v. 5; the resurrection, Matt. c. 28, v. 9; the disciples at Emmaus, Luke, c. 24, v. 31. Fio-. 744, Set of Scripture sliders, in 14 slides, two of which are movable, viz ;— 1, Milton's council, spirit moving on the waters, creation of sun, creation of moon and stars. 2, Adam and Eve in Paradise, Adam and Eve driven from Paradise, Cain slaying Abel, flood. 3, Tower of Babel, flight of Lot from Sodom, Abraham offering Isaac, Jacob's vision. 4, Moses found in the bulrushes, Moses and the burning bush, Moses receiving the Law, spies with the grapes of Eschol. 5, Samson slaying the lion, Samson and the carcase, Samson and gates of Gaza, Samson and death. 6, David playing the harp before Saul, judg- ment of Solomon, Job and his comforters, Daniel in lions' den. 7, New Testament, annunciation to Mary, birth of our Saviour, shepherds and angels praising God. 8, Flio-ht into Egypt, baptism of our Saviour, miraculous draught of fishes, Nicodemus and Christ at night. 9, Christ at the well and Samaritan woman, Christ in the ship in a storm, Christ heal- ing the sick, Christ raising the dead. 54 TEMPERANCE DIAGRAMS. No. 10, Christ blessing little children, Christ giving sight to the blind, Christ's Transfi- guration, Christ's entry into Jerusalem. 11, Judas betraying with a kiss, Pilate wash- ing his hands, Jesus scourged, Jesus crowned with thorns. 12, Jesus bearing his cross, crucifixion, as- cension, end. 13, movable, Israelites crossing the Red Sea, with the overthrow of the Egyptian host. 14, movable, Ark, with Noah, his family, and the animals entering. The set, $ 36.00 1130 Set twelve Scripture history sliders, thirty- six figures, ------ 24.00 1131 Noah, his family, and animals entering the ark, movable, ----- 3.25 1132 Israelites crossing the Red Sea with the Egyptians pursuing, movable, - - 3.25 1133 Single views on Scripture subjects, - - 0.88 1134 Splendid views in the Holy Land, and select Scripture subjects, viz. Jerusalem, Beth- lehem, Nazareth, Bethany, Damascus, Nineveh, Tiberius, Antioch, Patraos, Fords of Jordan, Seven Churches of Asia, ruins of Tyre, with many others of a similar character, each, from - - $3.50 to 5.50 1135 Views of the progress of intemperance in the drunkard's stomach, nine slides, - 18.00 1136 Views of progress of intemperance; 1, in- vitation to drink; 2, sickness and repent- ance ; 3, relapse; 4, expecting wife; 5, ruined family ; 6, robber, ... 18.00 1137 Set of twenty sliders on intemperance, - 25.00 1138 Cromatrope sliders, producing a variety of most brilliant revolutions and changes, pro- duced by means of two revolving wheels of painted glass turning in opposite direc- tions while in the lantern, a variety of pat- terns, paintings three and three and a half inch diameter, - - - - $5 to 6.50 1139 Rack cromatrope slides, - - - $6 to 7 50 1140 View of the muscles of the head and face, - 5.00 BENJ. PIKE'S, JR., PRICE CATALOGUE. 55 No. 1141 View of the nerves of the head and face, $5.00 1142 heart and lungs, 5.00 1143 skull, - 3.50 1144 ear, - 3.00 1145 neck, - 3.00 1146 skin, - 2.00 1147 bones of the hand and foot, 3.50 1148 Various slides giving motion to ships, ani- mals, &c. - $2.50 to 3.50 1149 Fig. 745, botanical sliders, representing 48 flowers, 12 slides, - 20.00 1150 Fig. 745, 12 in. long ; 3 in. wide, 14.00 1151 Botanical sliders, in 14 slides, or 50 views, illustrating botany, from germination of seeds, to the most beautiful flowers, trees, &c, with book explaining the whole, - 34.00 Slider 1.—1, cellular tissue; 2, cellular ducts ; 3, woody fibre; 4, spiral vessels. Slider 2.—5, spiral vessels in leaf; 6, vascular ducts ; 7, forms of roots ; 8, forms of stem. Slider 3.—9, section of exogenous stem ; 10, section of sassafras wood; 11, sections of endogenous stem. Slider 4.—12, fern stem; 13, forms of leaves; 14, leaf of gleditsia; 15, pitchers of Ne- penthes, &c. Slider 5.—16, pitcher of Dischidia; cuticle and stomata; 18, section of apple leaf; 19, section of oleander leaf. Slider 6.—20, forms of stamens; 21, struc- ture of pistil; 22, monstrous carpels; 23, structure of seed vessel. Slider 7.—24, process of fertilization ; 25, germination of seed ; 26, algae (sea-weeds) ; 27, lichen, Iceland moss. Slider 8.—28, fungus, amanita ; 29, rafflesia arnoldi; 30, chara flexis ; 31, moss, bryum caespiticum. Slider 9.—32, tree fern; 33, endogens, sac- charum officinale (sugar cane) ; 34, phoenix dactylifera (date palm) ; 35, colchicum au- tumnale (meadow saffron). 56 MICROSCOPES. Slider 10.—36, Zingiber officinale (ginger plant) ; 37, exogens, zamia horrida ; 38, atropa belladonna (deadly nightshade). Slider 11.—39, linaria communis (snap- dragon); 40, convolvulus major; 41, eri- cae (heaths). Slider 12.—42, anthemis pyrethrum (pelli- tory) ; 43, tamarindus indica (tamarind) ; 44, camellia japonica. Slider 13.—45, passiflora magniflora (gre- nadilla); 46, cardamine pratensis' (lady's smock) ; 47, ficris carica (Fig). Slider 14.—48, cactus speciosissima ; 49, ligusticum scoticum; 50, myristica mos- chata (nutmeg).- 1152 Set of kings and queens of England, from William the Conqueror to Queen Victoria, 9 sliders, 37 portraits, - - - - $ 18.00 1153 Set of four views of public buildings, viz. 1. St. Paul's, London ; Pavilion at Brigh- ton ; Southwark Bridge, London. 2. Westminster Abbey ; Falls of Niagara ; Waterloo Bridge, London. 3. St. Peter's Church at Rome; Fingal's Cave ; Parthenon at Paris. 4. Mount St. Michael, Cornwall; Military Hospital, Paris ; Island of Staffa. With description, ... price 10.00 1154 Set of select humorous subjects, in twelve sliders, with description, ... 24.00 1155 Set of History of France, in 42 sliders, hav- ing three or four views on each, - - 25.00 All the sliders are of full size, four inches wide, where not otherwise specified. BENJ. PIKE'S, JR., PRICE CATALOGUE. 57 MICROSCOPES. No. 1156 Fig. 746, flower microscope with one lens and point, --.---$ 1.12 1157 Fig. 746, ditto, two lenses and forceps, - 1.50 1158 Fig. 747, insect microscope with two lenses small size, ---_-. 1.00 1159 Fig. 747, ditto, large size, - - - 1.25 1160 Fig. 748, universal single microscope, in ma- hogany case, - - * - - - 3.50 1161 Fig. 748, ditto, with mirror, - - - 4.50 1162 Fig. 749, compound and single microscope, 9.00 1163 Fig. 750, improved compound and single microscope with rack adjustment, - - 15.00 1164 Fig. 751, compound microscope, - - 10.00 1165 Fig. 751, ditto, with one power only, and smaller size, ------ 4.00 1166 Fig. 752, large compound microscope, with rack adjustment, ----- 20.00 1167 Fig. 753, Culpepper's microscope. $15 to 25.00 1168 Fig. 754, Gould's compound and single microscope, ------ 12.00 1169 Improved compound and single microscope, mounted on folding legs, pillar, and joint, $38 to 42.00 1170 Achromatic microscope, with three powers, 20.00 1171 Fig. 755, achromatic microscope, with five powers, - - - - _ - 70.00 1172 Fig. 756, improved achromatic microscope, $130 to 150.00 1173 Fig. 757, solar microscope, with three inch condensing lens, in brass mounting, with three rack motions, - 50.00 1174 Ditto, with five inch condenser, - - 75.00 1175 Ditto, with three inch condenser, and one rack motion,......42.00 1176 Ditto, with three inch condenser, and com- mon mounting, ----- 25.00 1177 Ditto, with two inch condenser, and three rack motions, framework all of brass, - 40.00 58 MISCELLANEOUS. No. 1178 Solar microscope with two inch condenser, and one rack motion, - - - - $ 35.00 1179 Fi"-. 758, solar microscope, for opaque and transparent objects. - - - $60 to 100.00 1180 Fig. 759,'oxyhydrogen microscopes, - $80 to 150.00 1181 Fig. 760, set of 6 ivory sliders, each contain- ing four objects for the microscope, - 3.00 MISCELLANEOUS. 1182 Fig. 761, numeral frame with 144 balls, - 0.88 1183 Figs. 762 to 773, set of twelve geometrical solids,.......1.25 1184 Set of thirty geometrical figures in neat rose- wood case, ------ 6.00 1185 Fig. 774, dissected cone, - - $1,25 to 2.00 !186 Set of sixty-four one inch cubes, - - 1.25 1187 Set of 144 specimens of minerals, arranged and labelled in three trays, and mahogany box with lock,.....12.00 1188 & 9 Fig. 775 to 779, ear trumpets, - $1 to 1.25 1190 Fig. 780, ear trumpet with flexible tube, - 2.25 1191 Fig. 781, breast pump, - - - - 5.00 1192 Figs. 781 and 782, breast pump with cup- ping apparatus, three cups, - 9.00 1193 Breast and cupping apparatus, with scarifi- cator, .......15.00 1194 Lacquer for brass, per bottle, - - - 0.25 1195 White varnish for silvered articles, clock dials,