VIENNA INTERNATIONAL EXHIBITION, 1873. 
REPORT 
ON 
INSTRUMENTS OF PRECISION. 
BY 
CHARLES F. CARPENTER, M. IX, 
HONORARY COMMISSIONER OF THE UNITED STATES. 
WASHINGTON: 
GOVERNMENT PRINTING OFFICE. 
1875. VIENNA INTERNATIONAL EXHIBITION, 1873. 
R E 1' O R T 
ON 
INSTRUMENTS OF PRECISION. 
BY 
CHARLES F. CARPENTER, M. D., 
HONORARY COMMISSIONER OF THE UNITED STATES. 
WASHINGTON: 
GOVERNMENT PRINTING OFFICE. 
1875. TABLE OF CONTENTS. 
Art. Page. 
1. Extent and character of exhibit 5 
2. Strikes; Labor-saving machinery 5 
INTRODUCTION. 
CHAPTER I. 
CHRONOMETERS AND WATCHES. 
3. Historical ; Harrison's chronometer 7 
4. Dr. Hooke's work in horology 7 
5. Isochronism in chronometers 8 
6. Accuracy of chronometers 8 
7. Greenwich Observatory records 9 
8. British exhibits of chronometers .• 9 
9. Other foreign exhibits 10 
10. Pocket-chronometers and watches 10 
11. Compensation for temperature and position 11 
12. Swiss and English watches compared 12 
13. ValBe of the balance-spring 12 
14. Condition of theI American market 12 
15. Schools of horology and their work 13 
16. The tourbillon escapement 13 
17. Patek, Philippe & Co.'s watches 14 
18. J. M. Badollet & Co.'s exhibit 14 
19. Tests of watches at the observatory 15 
20. Awards made at these trials . 15 
21. Louis Audemars's exhibit 16 
22. U. Montandon and S. Jaccard, Montandon Brothers, and others... 16 
23. Breguet's and other French exhibits 17 
24. Report of M. Breguet on cheap watches 18 
25. English watches 19 
26. German exhibits 19 
27. Austrian watch-work 20 
28. Comparative merits ; Improvements 20 
CHAPTER II. 
29. General character of exhibits 21 
30. Historical 21 
31. Special characteristics in different countries 22 
32. Austrian and Bavarian exhibits 22 
33. French and Swiss and Dutch clocks 24 
34. American clocks 26 
35. Electrical clocks „ 26 
CLOCKS. 4 
CONTENTS. 
Art. Page. 
36. Tower-clocks 27 
37. Peculiarities of the tower-clock . 28 
38. The great Westminster clock 30 
39. Other clocks 32 
CHAPTER III. 
BALANCES AND MICROSCOPES. 
40. Balances; Sensibility 33 
41. Exhibits 33 
42. Microscopes ; Recent advances 34 
43. Exhibits 34 
44. Amici's device 35 INSTRUMENTS OF PRECISION. 
INTRODUCTION. 
i Extent and character of exhibit ; Strikes ; Labor-saving machinery. 
1. In this group, Germany, Austria, Switzerland, England, and 
France were foremost in their displays. The English department was 
surprisingly deficient, except in marine chronometers and watches; and 
even in this class, some of the most celebrated manufacturers were not 
represented. In the French department, there was also a notable neg- 
lect to make any display on the part of establishments well known for 
the superior construction and finish and the moderate price of their 
instruments. Switzerland was very creditably represented; of her 1,071 
exhibitors, 80 were in this group. This country, and some parts of Ger- 
many, appear to excel all others in combining cheapness with exceed- 
ingly fine workmanship, showing upon their productions the result of 
educating the minds of their skillful artisans. 
2. In some parts of Germany, the bad effect of strikes among the 
workmen is beginning to show itself. An advance of 25 per cent., claimed 
in some sections, will, if they succeed, certainly prevent many of their 
productions coming to this country, as, with the present import-duties, 
our artisans can successfully compete with them, both in quality and 
price. 
Germany, France, and Switzerland are gradually adopting labor- 
saving machines. Their most intelligent managers are fully aware that 
such a course must be taken in order to maintain themselves in the 
manufacturing world. 
The wonderful advance made in watch making in this country is one 
of the remarkable instances in which an entirely new industry has been 
taken up, an immense product put upon the market, and a national rep- 
utation established in about twenty years, competing successfully with 
countries that have been engaged in it since its infancy, aided by 
exceedingly low prices of labor. To sustain the position we now hold, 
apart from further progress, will require the utmost energy and skill we 
have at our command. CHAPTER I. 
CHRONOMETERS AND WATCHES. 
Historical ; Harrison's chronometer ; Dr. Hooke's work ; Isochronism ; Accu- 
racy ; Greenwich Observatory records ; British exhibits ; Pocket-chronom- 
eters and watches; Compensation; Swiss and English watches; Value of 
the balance-spring; American market; Schools of horology; Tourbillon 
escapement; Various exhibits; Tests of watches; Awards; Breguet on 
cheap watches ; Comparative merits of exhibits ; Improvements. 
3. Marine chronometers.-The great increase of navigation in the 
sixteenth • century established the fact that the one great want of the 
mariner was the means of ascertaining the position in longitude of his 
vessel when at sea. The urgent need of some such instrument, and the 
belief that its construction was possible, induced the governments of 
Spain, France, and Holland to offer, during the whole of the seven- 
teenth century, rich rewards in order to stimulate the zeal and to 
quicken the inventive faculties of their philosophers and mechanicians. 
In 1714, the Parliament of England offered the substantial reward of 
£20,000 to any inventor of an instrument which would, under all cir- 
cumstances in which it was likely to be placed, keep time with such 
accuracy as to determine the longitude of a place within the distance of 
half a degree, or thirty geographical miles. These rich rewards, and 
the hope of making discoveries that would give them fame and honor, 
induced the most skillful mechanicians of Europe to give their attention 
to the invention of the desired instrument. In 1761, John Harrison 
constructed a chronometer, of which the rate varied so little that, on 
being sent to Port Royal, in Jamaica, it proved, on the eighty-first day 
of the voyage, that the captain was wrong in his reckoning, by the 
usual method, a distance of ninety miles; the chronometer's error was 
less than eighteen miles. Harrison was adjudged to have complied 
with all the conditions required by the act of Parliament, and received 
the full reward of £20,000. 
4. Comparatively few persons are aware of the vast amount of 
mechanical skill and mental labor it has demanded, through a course of 
two centuries, to bring to its present state of perfection this the most 
perfect piece of mechanism known to man. Produced as it has been, 
after many failures and disappointments, at an infinite cost of time, 
money, labor, and perseverance, and finally executed in such harmonious 
consistency with certain known laws as to be able to indicate to the 
lonely mariner, by day or night, in storm or in calm, in heat or cold, 
almost the very spot on which his ship floats on the vast expanse of the 
trackless ocean, its marvelous precision and perfection may well be 8 
VIENNA INTERNATIONAL EXHIBITION, 1873. 
regarded as one of the greatest boons ever secured to his race by the 
ingenuity of man, and as one of the proudest triumphs of human reason. 
Down to the middle of the seventeenth century, horology could only 
be considered as a mechanical art, depending entirely upon good work- 
manship for its excellence; but, at that period, Dr. Hooke raised it to the 
rank of a science by propounding its laws, and enriching it with those 
valuable discoveries and inventions which rendered skillful manipula- 
tion a mere accessory, although an indispensable one, to carrying out 
the governing laws and principles which he had deduced from the 
highest branches of science. Only those who have studied the science 
and history of horology, and have been practically engaged in it, can 
form a correct idea of the difficulties that had to be overcome to secure 
the present state of perfection of instruments for keeping time. 
5. It was discovered that the effect produced by changes in tempera- 
ture was one great difficulty to overcome. In 1773, Berthoud estab- 
lished with certainty, by calculation and experiment, that one of his 
marine watches varied to so great an extent as 6 minutes and 33 
seconds in passing from 32° to 92° Fahrenheit, while a clock with 
a seconds-pendulum was known not to vary more than about twenty 
seconds under similar circumstances. 
The amounts in loss of time due to three causes operating conjointly 
were as follows: 
Seconds. 
Loss per diem by expansion of diameter of balance 62 
Loss per diem by loss of spring's elastic force 312 
Loss per diem by elongation of spring .... 19 
393 
or 6 minutes 33 seconds. 
The discovery and application of the laws of isochronism in the 
balance-spring by Dr. Hooke and Mr. Arnold in England, and Leroy 
and Berthoud in France, imparted the most essential quality for keep- 
ing a regular rate of time to the chronometer ; particularly was this so 
when the temperature-error, as above, was known. 
Isochronism is an inherent property ot the balance-spring, depend- 
ing entirely upon the ratio of the spring's tension, following the propor- 
tion of the arcs of inflexion. A balance-spring, therefore, of any force 
whatever, having the progression required by the law of isochronism, 
will preserve this quality, whether it be applied to a balance making 
rapid or slow vibrations. 
6. The great advantage of an isochronal spring is its innate power of 
resisting the influences which cause a change of rate, such as change 
of position, increased friction as the works become dirty, or the viscidity 
of the oil at low temperatures. 
Indeed, it is surprising to see chronometers return from sea with 
scarcely a change of rate, although some of them have been going for 9 
MARINE CHRONOMETERS. 
three or four years, and even for longer periods of time, and the vibra- 
tions of the balance had fallen off to a very small arc in consequence 
of the oil becoming so viscid that, in some instances, a slight degree of 
force has been required to draw the pivot out of the fourth wheel-hole. 
But what was still more remarkable, some of these chronometers, after 
being cleaned, have been observed to take up their original rate, even 
perhaps with a threefold amount of vibration. The mechanical execu- 
tion of the different parts of a chronometer could be done in as finished 
a manner a century ago as at the present time, yet they had very 
different time-keeping qualities. 
7. After the pri nciples of adjustment for temperature and isochronism 
were known, the skillful application of them has gradually improved 
the time-rate. 
By looking at the best rates obtained at the Greenwich Observatory 
during the years mentioned below, it may be seen what progress has been 
made in the performance of chronometers from the year 1800 to the 
present time. 
Up to 1835, nothing had been used superior to the compound balance 
as constructed by Ernshaw ; but it was then discovered that this com- 
pensation-balance had a regular error, in extremes amounting to several 
seconds, and from that time until 1873 nothing but balances with 
auxiliary compensation could stand any chance at the Greenwich trials, 
owing to the trials being not far from twice as severe in temperature 
as at the beginning of this century. Formerly, the chronometers were 
not tried in heat, but in severe cold and middle temperature; they are 
now tried in heat, such as is experienced at the tropics, and such cold as it 
is probable they will be subjected to in winter. This in itself is enough 
to double the error of the ordinary compensation-balance. 
The trial-numbers are made up at Greenwich by taking the differences 
between the highest and least rate, added to the greatest change of 
weekly rate multiplied by two; and those giving the best results are 
purchased by the admiralty for government use. 
The best trial, in 1800, was: temperature, 46° to 71° Fahrenheit; 
greatest difference from week to week, 5.2 seconds; trial-number, 20 
seconds. 
Temperature, not given, 1810; greatest difference from week to week, 
4.3 seconds; trial-number, 20 seconds. 
Temperature, 33° to 96° Fahrenheit, 1870; greatest difference from 
week to week, 3.8 seconds; trial-number, 13.1 seconds. 
Temperature, 35° to 96° Fahrenheit, 1873; greatest difference from 
week to week, 3 seconds ; trial-number, 11.1 seconds. 
If the last four years' rate of improvement should continue, we will 
soon arrive at a point where we will have to remain stationary, because 
the nearer we approach perfection the greater will be the difficulty in 
overcoming the remaining errors. 
8. W. Weichert, Cardiff, Wales, exhibited two very fine chronom- 10 
VIENNA INTERNATIONAL EXHIBITION, 1873. 
eters, one with a thermometer and barometer attached to it. By the 
superior performance of his chronometer No. 2300 at the Greenwich 
Observatory trials in 1873, it was placed iirst in order of merit. The 
duration of the trial was thirty weeks; the lowest temperature it was 
subjected to was 35°, and the highest 96° Fahrenheit ; trial-number, 
11.1; greatest difference between one week and the next, 3 seconds. 
This chronometer had Kullberg's flat-rim balance without auxiliary 
compensation, and is the first instance since the invention of chro- 
nometers in which any balance has given such results. 
The most extensive display of marine chronometers was made by 
V. Kullberg, of London. They were certainly beautiful specimens of 
horological art, comprising in their construction all of the most approved 
principles known at the present time. 
His chronometer No. 1799, flat-rim balance, without auxiliary com- 
pensation, gave the best results in 1872 at the Royal Observatory, 
Greenwich, in competition with chronometers made by thirty-seven 
other makers. The duration of the trial of each chronometer was twenty- 
nine weeks; the lowest temperature to which they were subjected was 
40° Fahrenheit, and the highest 95° Fahrenheit. 
C. J. Klaftenberger and J. R. Lozada, of London, and Sivel & Walter, 
of Cork, also had on exhibition finely-executed marine chronometers. 
9. Mr. Breguet, A. H. Rodanet & Co., T. Leroy, and Leroy & Sons, 
of Paris, were the only French makers who made any display. Their 
chronometers appeared to be well made; but they did not exhibit any 
remarkable qualities to distinguish them particularly from other makers. 
Each chronometer should have had attached to it a certificate from 
an observatory, giving in detail its variations during a trial of many 
weeks, which would have shown any points of superior excellence, that 
it might have possessed. 
Grandjean, Heinrich & Co., of Locle, Switzerland, Kiek & Casseres and 
A. Hohwii, of Amsterdam, M. Peterson, of Altoona, W. Brooking, of Ham- 
burg, and M. Domenico, of Leghorn, Italy, exhibited well-made chro- 
nometers, but none of them showing any new features worthy of 
particular mention. 
An electro-magnetic chronometer, by Josef Danischewsky, Wilna, 
chronometer-maker to the Russian navy, was an ingenious piece of 
work, and was arranged as a controlling time-piece ; communication 
being made and broken 'with an electrical clock at every full vibration 
of the balance. It was the only one of its kind in the exposition, and 
for some purposes, might be a very valuable instrument. Chronometers 
as made in our own country will 'compare favorably, both in plan of 
construction and excellence in finish, with any made in Europe. In 
fact, the work produced by some of our makers cannot be excelled any- 
where in mechanical perfection of form and finish; but none were sent 
to the exposition. 
10. Pocket-chronometers and watches.-In this department, the POCKET CHRONOMETERS AND WATCHES. 
11 
display from Switzerland surpassed all other nations, it being one of 
the most important industries of that isolated little republic. The 
mechanical excellence shown in their finest watches is certainly bordering 
on perfection, and their cheapness will enable them to be sold in all the 
markets of the world. 
There are observatories in Geneva and Neuchatel, where their first- 
class watches are put upon trial for many weeks; and they certainly 
have produced watches keeping time with marvelous accuracy, as shown 
by the certificates accompanying them, signed by the officials at the 
observatories. The finish that can be given to the different parts of 
a watch is all that can be desired. Superior excellence can only be 
obtained through the simplest, and most economical arrangement of the 
proportions and positions of the different parts, then adjusting the 
balance for heat and cold and position, and the hair-spring for isochro- 
nism. 
11. The proper arrangement of the weights, or small screws, in the rim 
of a compound balance counteracts the effects that are produced upon 
the hair-spring by an increase of temperature. 
This spring being several inches in length is affected by a slight increase 
of heat, making the watch run slow; this error is counteracted by the 
movable ends of the rim of a compound balance, which, as the heat in 
creases, move toward the center of the balance, thus'making a portion 
of it smaller in circumference, which causes the watch to run faster. But 
the practical application of this principle has not yet been brought to 
perfection, as, at a medium temperature, the adjustment might be all 
that could be wished for, yet, at extremes, 32° and 98°, there will be errors 
that cannot yet be overcome, but they are gradually being reduced by 
the skill of the most ingenious and scientific horologists. 
Whenawatchis hanging by its pendant, the friction upon the pivots of 
the balance-staff is greater than when it is lying upon one of its sides. In 
a hanging position, the friction is upon the sides of the pivots; in lying 
down, it is upon the end of one of the pivots. This difference in the 
amount of friction makes a difference in the length of the arc of vibration 
of the balance. 
In time, thickening of the oil and dirt will lessen the power of the train 
• upon the balance, and consequently cause it to vibrate in smaller arcs. 
Any decrease of power in the mainspring will also produce the same 
effect. This difference in the length of the arcs of vibration of the bal- 
ance will cause the watch to run fast or slow, unless the error is counter- 
acted by giving the hair-spring a certain invisible property called 
isochronism; that is, giving it a certain tension that will cause the small 
and large arcs of vibration of the balance to be performed in the same 
length of time. This condition of the hair-spring is brought about by 
giving it a certain length, and in some springs by giving the outer coil 
a certain curve. These adjustments require the services of the most 
skilled workmen, and enhance greatly the cost of a watch, as it takes 
many weeks of careful attention to arrive at a satisfactory result. 12 
VIENNA INTERNATIONAL EXHIBITION, 1873. 
12. It is this skillful care given in late years to a proper adjustment 
of the hair-spring, that has imparted to Swiss watches such excellence, 
that they now rival the best English watches in their performance. 
It must be remembered that English watches generally have a chain, 
and a conical wheel, called a fusee, upon which the chain is wound. 
When the watch is entirely wound up, the power of the mainspring is 
considerably increased, and the chain then draws upon the small end 
of the cone, or fusee, thus equalizing the power of the mainspring upon 
the moving parts during the time of their running; consequently, there 
is but little variation in the arc of the balance caused by the increased 
power in the mainspring when wound up. 
In Swiss watches, the chain, fusee, and maintaining-power work, ex- 
cept in few instances, are not used, thus reducing the cost of manufac- 
turing and liability to get out of order. The mainspring is inclosed in 
a barrel that has teeth upon its circumference, operating directly upon 
the train. When wound up, the mainspring has a much greater power 
than when nearly run down; consequently, the arc of vibration of the 
balance is much greater at one time than at another, which would cause 
great irregularity in time-keeping were it not for this isochronal adjust- 
ment of the hair-spring. 
13. If we wish to know how much the world is indebted to the in- 
ventor of the balance-spring, we have only to inquire what it does for 
society, for civilization, for art, for science, for navigation, and for com- 
merce. 
We may judge of its value as estimated by different governments by 
the immense sums of money, which have been offered and paid for im- 
provements on it, and the chronometer in which it is used. 
One of the most striking instances of the great value of accurate 
time-keeping is the facility and certainty with which, by its aid, a ves- 
sel can proceed to the locality of a fault in a submarine telegraph-cable, 
so that it may be grappled at the bottom of the sea, brought to the sur- 
face, and repaired. This is now such an ordinary feat that it excites 
but little comment when it is reported that a cable has been repaired; 
yet it is one of the greatest marvels of the nineteenth century. 
14. The wonderful advance made in watch-manufacturing in this 
country, the simplicity of their construction, the use of labor-saving 
machines, and the great number of movements made, excite the aston- 
ishment of all the enlightened masters of the art in Europe. The chain 
and fusee, with the maintaining power, are left out; all the pieces are 
made to a uniform size, and interchangeable, so that if one piece be 
lost or broken, it can be replaced, at trifling cost, by sending to the fac- 
tory for a duplicate. By using hardened and tempered hair springs 
and proper adjustments, great excellence is obtained in time-keeping. 
But few second-class English watches are now imported into this 
country, and even the sale of medium-priced Swiss watches has been 
seriously affected by our home productions. POCKET CHRONOMETERS AND WATCHES. 
13 
Foreign manufacturers are already beginning to use labor-saving 
machines, and adopting the simplest plans of construction. This change, 
in connection with educated artisans, will have its influence, so that 
they may still be able in the future to compete with us in cheapness and 
quality. 
15. The influence exerted by schools that have been established in 
different parts of Europe for teaching the science and art of horology 
will be very great; there being a marked superiority in the proficiency 
acquired by graduates of such institutions over those who have received 
their knowledge of the art by the old method. One of the most inter- 
esting displays in the horological department of the exposition was 
made by the pupils of the French National School of Horology at 
Cluses, which is located in Savoy, between Geneva and Chamouni. 
Mr. Benoit, the director, was a pupil of the elder Breguet, and has had 
charge of this establishment for twenty-five years. It is a government 
free school, where drawing, mathematics, and the scientific branches of 
the art are taught by three professors, and where the practical portion 
is taught by three skillful artisans noted for their proficiency. They 
had, at the time of the exposition, 72 pupils, and were making arrange- 
ments to accommodate 400. 
In the display made by this school was shown the individual pieces 
as they came from the hands of the pupils, from the roughest state to 
the completely-finished condition, forming the different qualities of 
movements, and all together showing that the school was producing a 
superior class of artisans. 
Here were exhibited sixteen different forms of escapements, in move- 
ments about the size of an eight-day marine chronometer. The escape- 
ments were so exposed that their construction and action could easily 
be seen. One was a remarkable contrivance, intermediate in form 
between the lever and duplex escapements; the balance making two and 
a half revolutions. No. 2 was made so as to show the intimate relation 
between the lever and cylinder escapements. No. 8 was a tourbillon 
escapement, invented by Mr. Benoit, which gave a very large arc of 
vibration to the balance. 
16. What is usually called the tourbillon, or revolving, escapement is 
reported to have given the best performance in trials of chronometers 
extending over three years at the Neufchatel Observatory. 
It is not in reality an escapement, but an additional contrivance, 
which may be as well used with one escapement as another. It was 
invented by the elder Breguet, whose inventions are as numerous as 
they are brilliant. Every branch of horology is rich with traces of his 
genius. The whole escapement and balance are set in a frame-work, 
which revolves every minute. The object of this is to make the watch 
correct its own " errors of position " by making the balance pass every 
minute through all its vertical positions. As an ingenious and delicate 
piece of mechanism, it excites one's admiration, but leaves a doubt in 14 
VIENNA INTERNATIONAL EXHIBITION, 1873. 
regard to its practical utility, being costly to manufacture and difficult 
to repair in case of accident. The same result in time-keeping can be 
obtained by using a perfectlybalance. 
17. In Geneva, nearly three thousand persons are engaged in the 
watch-making and jewelry business, and twenty thousand watches are 
made annually. 
Foremost among the eighteen exhibitors from this city was the house 
of Patek, Philippe & Co., who displayed a large number of exceedingly 
fine watches, with the addition of independent seconds, chronographs? 
and repeaters, fully sustaining their world-wide reputation for fine 
work. This house, founded in 1839, employs in their establishment over 
five hundred persons; of these, 348 men and 42 women work at their 
homes. 
Their factory is spacious, well ventilated, provided with reservoirs of 
water as a protection against fire, and each workman has a window. 
The number of watches made is about three thousand a year. 
They were among the first who constructed stem-winding watches; 
and since the introduction of this particular manufacture, their business 
has rapidly increased. The peculiar winding and setting arrangement 
used is ingenious, elegant, and effective. 
In each class of watches, all the parts are made to conform to a cer- 
tain measure, as in the American system. All of their labor-saving 
machines are made in their own establishment, and many of them are of 
their own invention. 
The final adjustments in regard to position and temperature are made 
with great care, as will be seen by the average performance of nine of 
their watches exhibited in the exposition, which, during forty-five days 
at the Geneva Observatory, gave the following results: daily variation, 
six-tenths of a second; difference between hanging and lying, seven- 
tenths of a second. Among their watches, we noted a chronograph, that 
recorded minutes as well as seconds. 
They also exhibited one of those wonderful little curiosities, a sing- 
ing-bird about an inch long. Upon touching a spring, it arose through 
the top of a snuff-box, and, after ending its warbling, suddenly disap- 
peared beneath the cover. In front of the box was a very small watch- 
movement, which indicated the day of the week, month, &c. 
Their chronometers and chronograph-watches in spherical cases were 
certainly unique affairs. 
They also make for the Russian post-office department a large-sized 
watch, running a week. It is so arranged that the courier cannot open 
or wind it; this must be done by the postmaster. 
18. The firm of J. M. Badollet & Co., of Geneva, made a large display 
of first-class watches, including independent seconds, chronographs, and 
repeaters. The cases, engraved by Mr. J. Bonnet, were the most ele- 
gant display of the engraver's art in this line in the exhibition. 
Chronometer No. 06,401, with fusee, cylindrical hair-spring, and En- POCKET CHRONOMETERS AND WATCHES. 
15 
giish detent-spring, gave a daily variation, according to the observatory 
certificate, of 0.39 of a second. 
An average of the performance of five watches on exhibition gave a 
daily variation of 0.42 of a second. 
They claim to have made, previous to the exhibition, a watch, No. 
64,025, which was sent to America, whose daily variation was only 
0.29 of a second. 
19. At the annual trial at the Geneva Observatory, watches remain 
forty-five days, and are submitted to the following tests: 
1st. The mean variation from one day to another is determined during 
forty-five days. Whatever may be the position or temperature, the 
limit fixed to enable them to compete is 0.8 of a second. 
2d. The error corresponding to a difference of one degree centigrade 
of temperature is observed, with a limit of 0.2 of a second. 
3d. The difference of rate between the horizontal and vertical posi- 
tions is ascertained, with a limit of 2 seconds. 
4th. The correctness with which a watch resumes its former rate after 
having been placed in a different position fifteen days is noted, with a 
limit of 1.5 seconds. 
5th. The correctness with which a watch resumes its mean rate after 
having passed through the oven is noted, with a limit of 1.5 seconds. 
If a watch exceeds'the limit at any one of these trials, it is rejected. 
The mean of all the trials determines the classification; slight importance 
being given to the first trial. 
20. In the competition this year, (1874,) the first prize was awarded to 
Messrs. Badollet & C.o. for a watch having a lever-escapement, and the 
balance-spring turned according to the Philipps formula. It was ad- 
justed by Francis Vindone, and during the three months it remained at 
the observatory its variation diminished. 
The first proof gave an error of 0.28 of a second; the second proof, 
0.10; the third, 0.4; the fourth, 0.32; and the fifth, 0.54. This is the 
third year that a watch adjusted by M. Vindone has obtained the first 
prize. 
Of the second prizes, one was awarded to M. Jules Romieux for a 
chronometer adjusted by himself; the errors of the five proofs being 0.42, 
0.01, 0.23,1.41, and 0.52. The other was given to M. Em Paintard for a 
watch adjusted by himself; the errors being 0.51, 0.06,0.07,0.08, and 1.49. 
This year, for the first time, a second competition was instituted. 
It consisted of taking the mean of all the rates of the watches sent in 
by each manufacturer, provided that not less than three were submitted. 
The tests were not so severe for these as for single watches. 
Six makers entered into this competition ; the best two being so nearly 
equal that the prize was divided between them. The successful com - 
petitors were Messrs. Badollet & Co., who sent in seven watches, six of 
which were adjusted by M. E. Vindone, and one by M. J. Rainbat ; 
and M. R. Ekegren, with five watches, four being adjusted by M. A. 
Favre, and one by M. R. Ekegren. 16 
VIENNA INTERNATIONAL EXHIBITION, 1S73. 
The mean variation of the seven watches of Messrs. Badollet for the 
first five trials were 0.486, 0.12, 1.877, 1.141, and 0.546; and the five of 
M. Ekegren, 0.536, 0.078, 1.140, 2.116, and 1.054. 
21. The house of Louis Audemars, of Brassus, canton of Vaud, Switz- 
erland, made the most extensive display of complicated watches. Their 
mechanical execution was of the highest order; it was a superb collec- 
tion of repeaters, chronographs, and independent-second watches. 
The movement having the most elaborate and complicated mechanism 
was a pendant-winding clock-watch, No. 10831, 21 lines across the dial. 
It struck the hours and quarters in passing them, and the hours, quar- 
ters, and minutes, whenever wished, by pushing a slide. It had an 
independent-second train, with large double or split hands-one stopping 
for observations-a small seconds-hand and a one-fifth of a second hand 
on the same axis. It had two time-dials, full calendar, showing the day 
of the week and of the month and the moon's phases; a metallic ther- 
mometer; a cylindrical hair-spring; anchor-escapement; 45 rubies; treble 
keyless winding-work, having three mainsprings. Its price was marked 
at 20,000 francs. 
No. 11623 was a pendant winder, 20 lines, and 33 rubies. It repeated 
hours, quarters, and minutes. It was specially designed for travelers, 
as it showed upon the dial the time at the principal cities of Europe. 
No. 11173, pendant winder, 19 lines, anchor-escapement, independent 
seconds, repeats hours, quarters, and minutes; shows day of the week, 
of the month, and the moon's phases ; 45 rubies. 
No. 10967 was a pendant winder, cylinder-escapement, repeats hours 
and quarters, eight lines in diameter, marked at 4/)00 francs. 
No. 11825 was a pendant winder, ten lines in diameter, with anchor- 
escapement ; it repeats hours, quarters, and minutes, and has a com- 
pensated balance and 31 rubies. It was marked at 5,000 francs. 
The last two are claimed to be the smallest watches in Europe of like 
character. 
There was also in their case, and made by the younger Audemars, a 
miniature pistol, that was one of the curiosities at the London Exhibition 
in 1851; it was composed of twenty-two pieces, and weighed only the 
half of one grain, (32 milligrams.) 
All the watches of this firm are made within their factory, or by work- 
men under their immediate supervision ; they use labor-saving machines 
as much as possible; they claim to be the only house in Switzerland 
who make repeating-watches complete within their own establishment. 
Their first watch, winding and setting by the pendant, was made in 
1838, and one was exhibited by them in the London Exhibition in 1851. 
Watches with three barrels, winding by the pendant, were first con- 
structed by this house in 1867, and an extra-complicated watch, No. 
10834, on exhibition, had this arrangement. 
22. U. Montandon and S. Jaccard, of St. Croix, exhibited a case con- 
taining 29 watches; they were minute-repeaters, with and without inde- POCKET CHRONOMETERS AND WATCHES. 
17 
pendent trains, watches striking the hours and quarters in passing, and 
small watches highly decorated with diamonds. In construction and 
finish they were very creditable, but not so remarkable as to require any 
particular mention. 
In the collection of Montandon Brothers, of Locle, there was a clock - 
watch, that is, one striking the hours and quarters in passing, and the 
hours, quarters, and minutes by pushing a slide. 
Dufour, Zentler & Bro., of Geneva, made an elegant display of fine 
watches, independent seconds, chronographs, &c.; the highly-orna- 
mented cases of their bijou watches showed exquisite design and work- 
manship. 
B. Haas & Co., of Geneva, exhibited a case of elegant watches, but not 
of exceeding merit; also a singing-bird in a snuff-box. An exquisitely 
small watch in the back of a beetle, made of gold and enamel, which 
exposed the dial when the wings were expanded, was a unique design, 
and a very small movement set in a ring was another curiosity in min- 
iature-work. 
Jeanjaquet & Co., of Neuchatel, made a fine display of repeaters, inde- 
pendent seconds, chronographs, minute-repeaters, &c. 
H. R. Ekegren, of Geneva, noted for his carefully-adjusted time- 
keepers, had on exhibition a case of finely finished watches. 
The cases and chatelaines exhibited by G. Sachs, of Geneva, were beau- 
tifully made, being in high relief, with colored gold in antique designs. 
Many other exhibitors made extensive displays of Swiss work; but 
as they presented no new features of particular interest, we made no 
special notice of theip. 
23. The well-known house of Breguet, rue de la Paix, Paris, made a 
small but very select display of watches, fully sustaining their high 
reputation as makers of excellent time-keepers. The cases of their 
watches are made so that they could not be opened except by a watch- 
maker, being wound up and set by the pendant, and regulated from 
the outside. Being so carefully protected from dirt and the action of 
the atmosphere, they will run a long time without being cleaned. 
Their finest work is made by graduates from the French School of 
Horology at Cluses. 
One of the most interesting curiosities in horological art in Paris may 
be seen at this establishment. It is a very complicated watch, showing 
many phenomena, and made nearly one hundred years ago by M. Bre- 
guet for a marquis in Marie Antoinette's guard. The stipulated price 
was 25,000 francs, but troublesome times came on and it did not pass 
out of M. Breguet's possession. It winds itself up by the motion com- 
municated to it by its wearer in walking about fifteen minutes, and 
shows the surprising degree of skill attained in watch-construction 
during the last century. 
Messrs. Leroy & Sons, Palais Royal, Paris, exhibited an elegant 
assortment of repeating-watches, minute-repeaters, and chronographs; 18 
VIENNA INTERNATIONAL EXHIBITION, 1S73. 
some of them constructed with such mechanical perfection as to be 
valued as high as 7.000 francs. 
The house of A. H. Rodanet & Co., of Paris, made a display of hand- 
some watches, one of them, four lines, one-third of an inch in diameter 
with twenty-two rubies and anchor-escapement, was a marvelous piece 
of delicate work. Being a branch of the house of Patek, Philippe & Co., 
of Geneva, their productions have been fully described. 
Japay Brothers & Co., of Paris, made a display of watches with cylinder- 
escapements, and separate pieces showing the successive stages of man- 
ufacture. 
These watches are remarkable for their simplicity of construction 
and the very low price at which they can be sold. The amount of work 
furnished for a certain price with tolerable time-keeping qualities is 
remarkable. 
M. Gratel, of Besangon, also made a display of watches worthy of 
mention on account of their low price. 
24. The following portion of a report made to the Institute of France, 
by M. A. N. Breguet, in the name of the Committee on the Mechani- 
cal Arts, on cheap watches made by M. Roskopff, will probably be of 
interest: 
" To procure a watch for the workman at a low price, and capable of 
giving him the exact time, so that he may be at his business at regular 
hours, was the problem to be worked out; and we here show it has been 
solved by M. Roskopff, a manufacturer of watches at Chaux de Fonds, 
canton of Neuchatel, Switzerland, who has completely gained this 
point of good work, combined with cheapness. 
" M. Roskopff makes for 20 francs what he calls the workman's 
watch. To furnish at this price a strong watch, giving regular time for 
every day's use, M. Roskopff was necessarily obliged to simplify as 
much as possible the work done by hand, principally in the finish, and 
to confine himself strictly to the necessary usefulness of everything con- 
cerning the questions of solidity and good application of principles. 
" The cases are made in 4 hunting' and ' open-faced' styles and very 
heavy ; in the train, he has suppressed one wheel, by changing the num- 
ber of teeth in the wheels usually employed. The dial-wheels, which 
move the hands, are placed upon the mainspring box, and the whole 
mechanism is contained between two plates; the escapement, so essen- 
tial to a watch, is of the anchor-variety. 
" He alone unites two qualities : first, facility of construction in the 
factory; the shape of every piece permits it to be cut by machinery ; 
secondly, excellence in time-keeping and moderate price. Combining 
these conditions, it gives the best results of any yet made. 
" The watch is used without a key, being wound by the pendant; 
when it is wound sufficiently, a little vibration is felt in the watch, caused 
by the displacement of the outer end of the mainspring, as, instead of 
using the ordinary stop-work to prevent over-winding, he employs the 
Patek spring, which never needs any repairs. POCKET CHRONOMETERS AND WATCHES. 
19 
" Cheap watches are not new ; some are made cheaper than those of 
M. Roskopff, but the quality corresponds with the price. What is new 
here is the delivery of good and substantial watches at such prices that 
those of smallest purses can afford to buy them. 
" Your Committee of the Mechanical Arts, appreciating the efforts he 
was obliged to make to arrive at this result, and the services rendered 
to the laboring classes, has the honor to propose that a vote of thanks 
be given to M. Roskopff for his communication, and that the present 
report be inserted in the bulletin, with the design of the watch. 
" BREGUET. 
" Approved at the sitting, January 24,1868." 
25. In the English department, only three establishments made a dis- 
play of watches. 
V. Kullberg, of London, exhibited some of his finest work. This is a 
house noted for making highly-finished and well-adjusted watches; but 
there being no observatory certificates attached to them, we were unable 
to judge of their excellence in time-keeping. 
C. J. Klaftenberger, of London, made a largedisplay of English watches 
of good quality, but they presented no points of superior excellence. 
The well-known house of French & Co., of London, made a very credit- 
able display of their productions, all good work; but we did not see any 
new features that called for special mention. 
26. The most meritorious work from Germany was exhibited by A. 
Lange & Sons, of Glashiitte, Saxony. Indeed, taking the price into 
consideration, it would be difficult, if not impossible, to find in Europe 
any that excel them. The construction of their watches combines good 
workmanship with the application of the most highly-approved princi- 
ples. The epicycloidal curve of the teeth of the wheels and pinions, and 
the care used in putting them together, make a depthing that is not 
surpassed. This is a very important matter in the construction of a 
train, as all the available power in the mainspring is utilized, so that a 
spring no stronger than is actually necessary for a correct performance of 
the escapement may be used. 
Their balances are well made, and so constructed that the most accu- 
rate adjustments can be made with facility; and once made, they are 
not liable, in unskillful hands, to be seriously injured. The ruby pin is 
fastened permanently into the arm of the balance, which is left thicker 
at this place. The hair-spring collet fits on a projection cut out of the 
arm of the balance. There are no shoulders or cuttings upon the balance- 
staff, except at the pivots. It is plainly made, slightly tapering from 
one end to the other, so that it may be fastened to the balance by 
being lightly driven into the hole in the center of the arm of the balance. 
The ease with which a new staff may be put in, and the fastening of 
the ruby pin in the arm of the balance, are important improvements, as 
repairs can be made by persons of moderate skill without danger of 
seriously destroying the adjustments of the balance. 20 
VIENNA INTERNATIONAL EXHIBITION, 1873. 
They use the anchor-escapement, and it is executed with the greatest 
care and skill by the most highly-approved mathematical formula. 
Their stem-winding arrangement is constructed upon the best princi- 
ples ; it has strength, smoothness in action, and but slight liability to 
et out of order by rough usage. Everything about the watch denotes 
great thoughtfulness and attention to details; and, taking it " all for 
all," it comes nearer to what a watch, for good time-keeping, at a mod- 
erate price, should be than any other that we have ever seen. 
27. The house of Carl Souchy & Son, of Vienna, made an interesting 
display of watch-work made at Chaux-de-Fond, Switzerland, showing 
the method of finishing the pieces, from the roughest state to the com- 
plete movement. A chronometer with tourbillon arrangement, and a 
clock-watch striking the hours and quarters in passing, and hours, 
quarters, and minutes when wished for, showed excellent workmanship. 
The watches displayed by Austrian exhibitors were principally made 
in Switzerland. Their niello-work upon the cases and chatelaines was 
very durable and pretty in design ; but their cases too often contained 
Swiss cylinder-movements of low quality. 
28. Switzerland appears to lead all other nations of Europe in adopt- 
ing labor-saving machines, making every piece in a movement precisely 
like those in another movement and interchangeable, upon the same 
principle that watches are made in the factories of our own country. 
The English are slow to take up any new features in manufactur- 
ing which orignate in another country; but an enterprise has lately 
been started in Birmingham, aiming at manufacturing watches upon the 
American system. The fact that they must adopt the new system, if 
they wish to compete with other nations, has at last been impressed 
upon them. At a late meeting of the British Horological Institute for 
the distribution of prizes by the lord-mayor, a short speech was made 
by Sir John Bennett, in which he said : " Thirty years ago, England was 
unrivaled in watchmaking, but now foreign nations were not only 
equaling them, but driving them out of the markets of the world. In 
clocks, not one in a thousand sold in England itself was of English make. 
The Swiss were their great and most dangerous rivals; and in order 
that they might be able to compete with them, they should promote the 
employment of women in the trade, and technical education should be 
diffused more widely than was now the case." 
The use of stem-winding watches has largely increased within a few 
years, and the favor with which they are received, as demonstrated by 
the demand, shows that it will not be a long time before they will almost 
entirely take the place of the old style of watches, which are wound with 
a key. The good results obtained by the lever-escapement, and its 
slight liability to be deranged by rough usage, has led to its general 
adoption; but few chronometer-escapements are now put in watches, 
the lever being looked upon as more serviceable for pocket-use. 
In the watches made in the United States within a few years, there POCKET CHRONOMETERS AND WATCHES. 
21 
has been a tendency to an increase in the number of pieces used in 
their construction; this is also the case in stem-winding watches, as 
made by some factories. They could be simplified, be better in use, 
and made at less cost. The quickness with which inventions are adopted 
in our country has led to the use of various devices, which, after being 
tried for a short time, have been abandoned; the same fate awaits some 
of the forms of construction now used. 
But time will settle this matter, and there will yet be constructed a 
watch embracing all the good points, to the neglect of those that have, 
after a fair trial, failed to come up to what was expected of them. 
That establishment which has the genius to combine the most per- 
fect forms of construction of the different parts into a complete move- 
ment will certainly gain a wide and well-deserved reputation, and be 
richly rewarded. CHAPTER II. 
CLOCKS. 
General character of exhibits ; Historical ; Characteristics of different 
countries; Electrical clocks; Tower-clocks; Peculiarities; The Great 
Westminster and other clocks. 
29. There seems to have been but little improvement of late years in 
clocks for astronomical or domestic use. The large display of finely- 
executed clock-work with Graham's dead-beat escapement shows that 
it is still most in favor; and although there were many contrivances on 
exhibition for giving impulse to the pendulum, some acting every half- 
minute, others every minute, yet it is not probable that any of them 
will supersede Graham's invention. 
Austria far excelled all other nations in the display of large clocks 
with seconds-pendulums; the large number of movements showing 
workmanship of the first quality was truly surprising. 
The cases of many of them were constructed in the most elaborate 
manner, and were remarkable specimens of horological cabinet-work. 
It will be seen, from the figures attached to them, that their fine 
clocks are much more costly than one would suppose from the low price 
paid for labor. This arises from the limited use of labor-saving ma- 
chines ; almost all the parts being constructed by skillful hands. 
Clocks that strike the quarters and repeat the hour are extensively 
made in this country. Clocks going a year with once winding are also 
numerous. 
30. A small house on the exhibition-grounds was exclusively used to 
show the progressive history of Black Forest clock-making, beginning 
with the rude clocks of centuries ago, having a verge-escapement and 
a bar with weights suspended at the ends to serve as a horizontal bal- 
ance, and ending with the most approved styles of the present day. 
Two centuries ago, this industry was confined to the production of a 
small number of rudely-constructed clocks. Siuce then, it has steadily 
increased until it has become one of the most important manufactures 
in Germany. In 1796, the number of clocks of all descriptions made in 
the Black Forest district was 7,500; in 1808, the number had risen to 
20,000; in 1862, the total was 1,000,000; and, in 1872, was produced 
the astounding number of 1,800,000 clocks of almost infinite variety, 
from the antiquated wooden movement, going only twelve hours, to the 
costly regulator, and embracing specialties for nearly every country in 
the world; 400,000, or nearly one-fourth of the whole, were made at 
Furtwaugen. 
31. The greater number exported to Great Britain are provided with 
weights and chains, and go twenty-four hours. Switzerland is a cus- 
tomer principally for trumpet and cuckoo clocks. CLOCKS. 
23 
The demand in Austria is for the better class of chain-clocks, while 
Italy takes almost exclusively spring-clocks. 
France has a predilection for those of a large size, which are sold un- 
der the name of Swiss clocks. To Belgium and Holland are sent clocks 
with bronze cases, ornamented with tin and porcelain shields. Russia 
is a large customer for the best eight-day clocks, and is also the depot 
from which some of the Asiatic countries are supplied with the Black 
Forest manufactures. 
Turkey and Malacca take ship's clocks as well as cuckoo; Sweden, 
Norway, and Denmark show a preference for hexagonal and octagonal 
cases ; Spain and Portugal take chain-clocks only. 
Even our own country, where clocks are made in immense numbers, 
and as cheaply as any place in the world, imports Black Forest goods 
largely, chiefly cuckoo-clocks and regulators. Mexico and South Amer- 
ica take a fair proportion of cuckoo and spring clocks. India, China, 
and Japan demand cuckoo and ship's clocks, and a better manufacture 
with cases after the English pattern. 
There are, in this district, 1,429 clock-manufacturers, employing 7,526 
hands ; but it is computed that altogether 13,500 persons are dependent 
upon the clock-trade. 
Even with the whole world for a market, the distribution of two mill- 
ions of clocks a year is an achievement that the founders of the Black 
Forest clock trade would certainly never have anticipated. The great 
stimulus given to clock-making in this district within the past thirty 
years was in all probability owing, in a measure, to competition with 
cheap clocks made by machinery in the United States. 
32. Franz Zajicek, of Vienna, exhibited a well-made and very com- 
plicated astronomical clock, showing many phenomena. It had a Gra- 
ham escapement, and a gridiron-pendulum with a lenticular bob highly 
ornamented with designs from the zodiac. The movement was a won- 
derful complication of wheels, pinions, and levers, and was inclosed in 
a massive and elaborate case of cabinet-work, forming altogether the 
most imposing piece of horological mechanism in the exhibition. It 
was marked at 25,000 florins-about $12,000. 
The Bruder Stern, of Vienna, exhibited a large number of highly-fin- 
ished regulators, with Graham escapements, and steel pendulums compen- 
sated with mercury. One running three months was marked 3,400florins; 
another running one year, with time-train only, was marked at 3,150 
florins. The cases were magnificent in design, and ornamented with 
exquisite inlaid work. 
In Carl Stifft's display was a fine regulator, with a wooden pendulum, 
in an elegant case, which struck hours and quarters. It was marked at 
1,800 florins. In the Austrian clocks, the hour is generally struck upon 
a spiral piece of steel. 
Anton Schlesinger, of Vienna, displayed several regulators of exceed- 
ingly good workmanship and elegantly cased; the highest price being 
1,300 florins. 24 
VIENNA INTERNATIONAL EXHIBITION, 1873. 
In the collection of Leopold Seibert, of Vienna, there were two highly- 
finished regulators; one, running a year, struck hours and half-hours; 
the other also ran a year and struck hours and quarters. Metallic pen- 
dulums with mercurial compensation were used. The cases of these 
clocks were magnificent specimens of cabinet-work. 
Several makers are adapting the wooden pendulum to some of their 
finest work. If this material could be relied upon for regularity in its 
action, a very simple compensated pendulum could be made of it by using 
a lead bob about 14 inches in length ; but from many experiments that 
have been made with wooden pendulums prepared with the greatest 
care to resist moisture, &c., it has been found that they cannot be 
depended upon for accuracy. 
An iron rod with zinc compensation has been received with much 
favor in late years, and has given such good results that the clocks pre- 
pared by the English government for the transit-of-Venus expeditions 
have such an arrangement in preference to the usual jar of mercury. 
Carl Souchy & Son, of Vienna, exhibited some well-made regulators 
with jeweled Graham escapements, the highest price being 850 florins; 
the cost of the movement alone, which goes one year, was 300 florins. 
His cases in light colored woods were artistically designed and well 
made. 
J. Freitag, of Vienna, showed pieces in course of transition to com- 
pletely-finished clocks. A large portion of the work was struck out of 
sheet-metal with dies, showing the adoption of a labor-saving process. 
Carl Urban, of Vienna, exhibited an elegant regulator with time-train 
only, running one year, having steel pendulum compensated with mer- 
cury ; the price was 700 florins. 
In J. F. Schondorfer's collection, there was a regulator with a jeweled 
Graham escapement; the pieces lying separate, so that their highly-fin- 
ished condition might be seen. There was also a regulator, with pivot- 
holes and pallets jeweled, running one month. 
Professor Fischer, director of the Horological School in Vienna, dis- 
played separate pieces of a clock, which showed a high degree of per- 
fection in form and finish. Well-executed drawings of escapements, pen- 
dulums, &c., by the pupils of the school, showed their proficiency in 
this art. 
Carl Hartel, of Vienna, exhibited a large and well-made regulator, 
striking hours and quarters; price, 2,400 florins. 
A flue regulator, striking hours and quarters, with gridiron-pendulum, 
made by Franz Lengsfeld, of Vienna, deserved special notice for fine 
workmanship ; price, 2,000 florins. 
L. Lenbach,of Munich, exhibited a large and well-made regulator, with 
an escapement that seems to be considerably in favor in Bavaria. The 
pendulum is suspended upon a knife-edge. The upper part of the pen- 
dulum is extended above the point of suspension; at this eud, there is 
a ratchet-wheel with thirty teeth; at every vibration of the pendulum, 
a click, which is fastened to the movement, drops into the wheel and CLOCKS. 
25 
moves it one tooth; in a minute, the wheel makes a complete revolution; 
a pin fastened to the side of the wheel then comes opposite a detent, 
which lets off the train, giving impulse to the middle of the pendulum. 
It works very prettily, but is not likely to take the place of other well- 
known forms of construction. 
Samuel Kralik, of Pesth, had a very creditable display of clocks showing 
excellent workmanship. In this collection were sixteen well-made models 
of different escapements for demonstration; the balances being about 
four inches in diameter. 
Two large-sized mantel-clocks were meritorious for good workmanship 
and ingenuity. One had a large balance, with two escapement-wheels, 
acting something like a Swiss chronometer; the teeth of one of the 
wheels acting on the detent, and the other upon the roller-impulse 
jewel. The other clock had a pendulum; the escapement acting upon 
three jeweled detents, which, although delicate and giving impulse in 
one direction, was too complicated for practical use. Three large regu- 
lators had compensated pendulums constructed in an elaborate manner; 
one was marked 600 florins. A small regulator, with two barometer- 
tubes for a pendulum, was a novelty. The tubes vibrated upon a knife- 
edge adjusted about six inches below the top of the mercurial columns. 
All the rest of the regulators had Graham escapements. 
Franz Laschinger, of Ofen, exhibited a finely-constructed regulator, 
with time-train only; price, 600 florins. 
S. Blum, of Constantinople, exhibited a clock, and a separate pendulum, 
curious in design, but rude in mechanical execution. 
33. Switzerland displayed a large number of clocks for domestic use, 
including some ingenious trumpet and cuckoo clocks; but there did not 
appear to be anything particularly new about them. 
In France, mantel-clocks are a speciality. For elegance of design, 
good workmanship, and moderate price, they are not excelled by any 
nation. 
The house of Breguet, of Paris, had a small but interesting display. A 
mantel-clock, with a large tuning-fork to control the escapement, was a 
great novelty. This contrivance is the invention of Mr. A. N. Breguet, 
and the mechanical execution of the clock was by Mr. Edward Brown. 
The tuning-fork was about a foot long, and gave one hundred vibrations 
in a second. About midway upon one of the prongs, there waS a sliding- 
weight, by which the number of vibrations could be regulated. Pro- 
iecting from the end of the prong was a small pin, which acted in the 
fork of a lever. The lever made one hundred vibrations in a second, 
corresponding to the tuning-fork. Attached to this lever was a pair of 
pallets, which acted upon an escapement-wheel having ten teeth, and 
making four revolutions in a second. The tuning-fork in this case reg- 
ulates the speed of the train. The pallets and escapement-wheel act in 
a manner similar to the escapement of the striking-train in a repeating- 
watch. It was found by experience that the vibrations of the fork 
should be confined to about one degree to give the best results. These 26 
VIENNA INTERNATIONAL EXHIBITION, 1873. 
vibrations are so completely isochronal that an increase of power, from 
4 pounds to 60 pounds on the train, made no difference in its time-rate. 
The second-hand made a complete revolution in one second. The dial 
being divided into one hundred parts, with a proper contrivance for 
starting and stopping, it might be of sendee in recording time to the 
hundredth part of a second. 
This house also exhibited a beautiful mantel-clock, with a double 
escapement-wheel so constructed that both pallets received an outward 
impulse; the front pallet being dispensed with. The mechanical execu- 
tion of this clock was probably the best in the exhibition; and the 
remontoir arrangement, which acted every fifteen minutes, was remark- 
able for its ingenuity and beauty of construction. The pivot-holes of 
the escapement were bouched with platinum. Oil having no action on 
this metal will preserve its purity for a long time. 
Leroy & Sons, of Paris, had the largest display of first-class, richly- 
gilded, and enameled mantel-clocks. Some of them had novel and 
expensive escapements. A few were upon the gravity-principle, and 
others were of ordinary construction. Prices ran from 30,000 francs 
down to moderate prices. 
Guilmet, of Paris, displayed two clocks that attracted considerable 
attention. Each had a female figure standing upon the top of the clock, 
holding in her hand the upper end of a pendulum, which vibrated to and 
fro without any apparent cause. The round base, upon which the figure 
stood, rested upon a pivot, and was connected with the escapement. It 
had a slight motion upon its axis, imperceptible to an observer. By 
this means, the point of suspension was moved to and fro at every move- 
ment of the figure, which kept the pendulum in motion. 
A. Bailly and Theo. Leroy, of Paris, exhibited well-made regulators, 
with Graham escapements and mercurial pendulums. 
The French have a speciality in beautiful little traveling-clocks, at 
various prices, some of them very expensive. 
Kiek & Casseries, of Amsterdam, exhibited a well-constructed regu- 
lator, and J. Spouhase, of St. Petersburg, a regulator in splendid mala- 
chite case, but the movement was of ordinary construction. 
34. The United States were represented by only one exhibitor of clocks 
for domestic use, the Seth Thomas Clock Company of New York. In 
this collection were all the forms and qualities of clocks manufactured 
by this establishment. 
Although this display was a prominent feature in the department, it 
did not give a correct idea of the degree of perfection that American 
makers have arrived at in this art. 
It was much to be regretted that there were none of our fine astro- 
nomical clocks and regulators on exhibition, as they would have dem- 
onstrated that we are second to no nation in this industry, either in 
quality or price. 
35. Electrical clocks.-Probably the first clock whose pendulum 
received its impulse from electricity was contrived by Mr. Bain. The ELECTRICAL CLOCKS. 
27 
bob was made with a hole through it, and passed over two soft-iron 
cylinders, alternately magnetized by an electrical current at each beat of 
the pendulum. This principle has been adopted to a considerable extent, 
and, with an earth-battery made of copper and zinc plates buried in the 
ground, satisfactory results have been obtained. Essentially the same 
principle can be applied to a common pendulum-bob by making two 
horizontal arms from it enter two hollow magnets; a very small amount 
of electricity applied through a standard clock to a common one with 
this kind of pendulum will be sufficient to keep them in exact agreement. 
An accurate regulator can be made to control a large number of sec- 
ondary, or sympathetic, clocks, either upon the foregoing plan, which 
has the great advantage of not requiring absolute certainty or continu- 
ity of electrical action at each beat of the pendulum, or by electricity 
operating upon their escapements so as to cause the pallets to move 
the escapement-wheel, the pinion of which drives the wheels to which 
the hands are connected. This latter system has also been extensively 
applied. 
A gravity-escapement, invented by Mr. Shepherd, in which the pallet 
is raised by a temporary magnet, and then acts on the pendulum when 
swinging in one direction, is well spoken of. He made another import- 
ant improvement by arranging his magnets so as to repel and attract 
alternately, instead of leaving the separation to be done by gravity. 
Single clocks, going entirely by electro-motive force, have a certain 
fascination about them at first sight, being apparently a kind of per- 
petual motion ; but, in reality, it only illustrates the rather uncertain 
communication of electrical force derived from chemical action; and, 
notwithstanding the large amount of thought and mechanical skill that 
have been expended in this direction, it is not likely, except as a curios- 
ity, that it will supersede, for ordinary use, the old methods of applying 
power, that is, by means of a weight or spring wound up at certain in- 
tervals. 
An electrical clock with striking-work, exhibited by Autenreith & 
Himmer, of New York, United States, would have attracted more atten- 
tion if it had been in working condition, so as to show its mode of 
action. There was considerable merit claimed for it, and it certainly 
presented an appearance that predisposed one in its favor. We made 
some effort to get it into a more presentable condition, but without 
success. 
E. Deschiens, Dumoutin and E. Barbier, and A. Postel & Co., of 
Paris, made displays of electrical clocks with different systems. 
Matth. Hipp, of Neuchatel, exhibited various forms of electrical clocks. 
His large clock was something on the Bain principle. A horizontal 
armature was fastened to the lower end of the bob of the pendulum, 
with a temporary horseshoe-magnet fastened vertically beneath it. As 
the pendulum vibrated, the armature passed over its poles. About the 
middle of the pendulum was a small hanging click that caught upon a 
spring and closed an electrical circuit when the motion of the pendu- 28 
VIENNA INTERNATIONAL EXHIBITION, 1873? 
lum decreased to a certain arc. Having received an impulse from the 
magnet, the pendulum would vibrate from five to seven beats before its 
arc would diminish enough to allow the click to catch hold of the breaker 
and close the circuit again. This arrangement appeared to work very 
well, and is generally adopted in the construction of his clocks. 
J. Ferrucci, of Udine, Italy; A. Gerard, of Luttich, Belgium; Paul Mil- 
ler, of Cologne; J. B. Kerz, of Mayence; and B. Egger and M. Illitsch, of 
Vienna, exhibited well-made electrical clocks, but no improvement of 
particular merit. 
An electrical clock with registering-apparatus, for astronomical pur- 
poses, by Professor Arzberger, of Brunn, was an interesting piece of 
mechanism, and appeared capable of doing all that he claimed for it. 
36. Tower-clocks.-The small number of tower-clocks exhibited 
was remarkable for an exhibition of this magnitude. Neither England 
nor France, both of which nations excel in this work, was represented. 
A few makers in our own country turn out mechanism of this class that 
is not surpassed anywhere for excellence in principles of construction 
and good workmanship; yet not a single movement was exhibited in 
the United States section. Tower-clocks, if constructed properly, are 
capable of a wonderful degree of accuracy; but, as a general result, 
their performance is unsatisfactory. Not unfrequently cases similar to 
the following occur: the hands may show quarter to four, and the ham- 
mer strike thirteen on the bell; it is by this combination that it is indi- 
cated that it is 3 o'clock precisely. The cause of this trouble is often 
owing to faulty principles in construction; some escapements being 
liable to trip and throw the clock out of time. The striking-arrange- 
ment may also have defects. These faults, with an incompetent per- 
son to attend to the clock, produce results that are very much at vari- 
ance with the degree of correctness expected in a piece of mechanism 
of this kind. 
37. Being an expensive piece of construction, often costing several 
thousand dollars, it is advisable that its peculiarities should be more 
extensively known. 
One of the ablest and most reliable of English authorities says: " I 
suppose it may be said without exaggeration that there is no machine 
made and sold in England, perhaps no article whatever in common use, 
which so few of the purchasers know how to judge of, and therefore in 
which imposition is so easy, as turret-clocks." 
In constructing these clocks, it is generally thought it is only neces- 
sary to enlarge the machinery of an ordinary house-clock, and the end 
is accomplished; that they differ from small ones only in the weight of 
the hands and of the hammers. But there is a very important fact that 
interferes with the soundness of this conclusion. As the strength of 
machinery is increased, its weight is increased in a ratio as much higher as 
the cube is higher than the square of either of its dimensions; and when 
the weight is increased, the friction is increased-an important element 
to be considered. In small clocks, the force, or weight, required to work TOWER CLOCKS. 
29 
a hammer weighing a couple of ounces is generally about the same as 
that required to keep the pendulum in motion; and so the two parts or 
trains are about equal in strength. In large clocks, the lifting of the 
hammer generally requires a much larger amount of power than that 
needed to drive the hands and pendulum; they should, therefore, have 
much heavier and stronger machinery. 
Clock-makers make a great mistake in making the trains of uniform 
size, as the striking power is then so weak that only a very small bell 
can be used properly. Clocks constructed in this manner, placed in the 
hands of some persons, they try to improve their striking qualities by 
adding weights until the capacity of the clock is overtaxed, and in 
many instances serious results have followed such an experiment. 
In some clocks that have not been made in proper proportions, it has 
been found advisable to change the striking part from one week to one 
day. It is said that there are, with but few exceptions, no tower-clocks 
in England strong enough to perform the work properly, where pins in 
the second-wheel are used to raise the hammer. Some have been changed 
so that cams or pins on the great wheel raise the hammer, thus making 
it strike the hours powerfully for one day, instead of feebly for a week. 
For bells weighing above a ton, it is advisable to have a striking- 
train wound up every day, except where there is an unusually long fall 
for weights. This may be shown thus: A 40-pound hammer raised to 
a height equivalent to 5 inches is the least that will bring out the sound 
properly with a bell of that size; and that is too little if the bell is a 
thick one. Under the most favorable circumstances, and striking from 
the great wheel, it may be reckoned that the actual clock-weight will 
have to be double the theoretical; or, 
40 pounds x 10 inches x 78 x 15=468000 
for 7| days, which will be 975 pounds with a fall of 40 feet; and if 
several cranks or pulleys are used, the weight will have to be much 
more. Such large weights are not safe in most places, and require a 
very strong clock to sustain them ; besides, in some striking-trains, the 
weight required is nearly three times that calculated theoretically. 
The conclusion has thus been arrived at, that the best plan is to make 
the time-train carrying the hands run a week with once winding, and 
the striking-train one day, or four days at the farthest, for large bells. 
Bells weighing over a ton require hammers about one-fortieth of their 
weight to bring out the tone properly. Generally, they weigh much 
less, and therefore we seldom hear a bell sound so loud, when the clock 
is striking as when ringing. 
Cage-frames, consisting of vertical and horizontal bars, in which the 
wheels are placed over each other, are giving way to horizontal ones, in 
which each wheel can be removed without disturbing the others by un- 
screwing and taking out the bushings. The French commenced making- 
clocks on this principle nearly thirty years ago, and where there is 
room the method is to be preferred. 
In England, the introduction of iron in place of gun-metal or brass 30 
VIENNA INTERNATIONAL EXHIBITION, 1873. 
has reduced the price, so that clocks formerly costing £500 can now be 
put up for £150. For keeping time only, without regard to appearance, 
iron without doubt will do well for the larger wheels at a great saving in 
cost. Friction, liability to rust and break, have been urged against iron 
wheels, but with the gravity and remontoir escapements, the increased 
friction will not affect the time-keeping qualities. As to rust, all, except 
the acting surfaces, may be painted and oiled, as in other iron-wheel 
machinery. In spinning-machines used in factories, cast-iron wheels 
may be seen much smaller than those required in a large clock, and 
they perform admirably. 
Remoutoir-trains have, in late years, to some extent taken the place 
of ordinary trains; they have been much in favor. In this arrangement, 
the hands usually move every half-minute, at which time the remoutoir- 
train is wound up enough to run the escapement-wheel half a minute; 
at the end of that time, the hands suddenly make an advance, and the 
remontoir is wound up again, and so on. 
The escapement-wheel, which may be the usual Graham dead-beat 
pattern, is moved either by a weight or spring, and is detached from 
the variable force of the train carrying the hands. Some of the French 
manufacturers introduced, more than twenty years ago, a simplified 
form of gravity-remontoir, which gave good results when carefully 
made. There are several forms of remontoirdrains, which have done 
well; they may be found fully described in recent works on horology; 
but even these .are being superseded by gravity-escapements, which 
have done well in regulators, and in turret-clocks have certainly given 
wonderful results. 
It is asserted that altering old turret-clocks by putting this escape- 
ment in place of the usual dead-beat, and using an iron pendulum com- 
pensated by a zinc tube in place of the ordinary wooden one, has reduced 
the variation from minutes to seconds. These gravity-escapements, it 
is said, have an error partially compensating the barometrical one, 
which in some clocks amounts to nearly a second a day for a rise of 
one inch of mercury in a barometer; whereas the rate or error of the 
usual dead-beat escapement is in the same direction as the barometrical 
one. 
38. Through the kindness of the commissioner of public works, we 
were enabled to examine the great Westminster clock in London; a 
privilege seldom granted. This clock having been constructed with the 
greatest care, upon the best scientific and mechanical principles known, 
and having given the best results ever obtained, it may serve as a valu- 
able guide to those wishing to construct clocks reliable in performance. 
Lord Chief-Justice Coke tells us that the first Westminster clock was 
paid for by a fine imposed upon a corrupt predecessor of his own in 
1298. In A. D. 1365, a stone tower was erected here by Edward III, 
which contained a clock that struck the hours upon a great bell. There 
is no doubt that the place where the present clock-tower stands has 
been for more than five hundred years the site of a great public clock. TOWER CLOCKS. 
31 
The present clock, designed and its construction superintended by Mr. 
E. B. Denison, under a contract between Mr. Dent and the commis- 
sioner of public works, was first set going in May, 1859; the total cost 
being £22,050. The actual cost of the movement and striking-work 
was £4,080; of the hands and dials, £5,334; and of the bells, about £6,000. 
The balance of the fund was expended in experiments and failures, the 
results of opposition and of suggestions, which are said to be inevitably 
met with in the production of any large public work in that country. 
The horizontal frame that supports the three trains is 15 feet 6 inches 
long and 4 feet 7 inches wide. The time-train is wound up once, while 
the hour and the quarter trains are wound up twice a week. 
The great striking-wheel has ten circular cams, 2| inches wide, with 
hardened-steel faces. The cast-iron head of the large hammer weighs 
780 pounds, and is lifted 9 inches vertically, or 43 inches from the bell. 
Each striking-weight weighs nearly a ton and a half, which is about 
half what would have been required if the usual striking-work with 
pins had been used instead of cams to raise the levers. Wire-ropes, 
half an inch in diameter, are used to sustain the weights, and also to 
connect the clock with the hammers. 
The quarters, which are struck upon four bells, weighing 8,000, 3,700, 
2,800, and 2,350 pounds respectively, repeat the celebrated St. Mary's 
chimes at Cambridge. The first great bell was a defective casting, and 
cracked. The present one will probably be replaced before long, as it is 
porous, unhomogeneous in composition, and partially cracked through. 
It is 9 feet in diameter, and weighs 30,000 pounds. 
The mass of weight, that has to be moved in a clock as large as this 
at each beat of the pendulum, is so great-being two tons-that it 
requires more power in the weight, than would be safe acting directly on 
the escapement. To overcome this difficulty, aud to completely isolate 
the pendulum from the great and varying pressure of the train, various 
contrivances have been used. The first tried in this clock was the three- 
legged "dead" escapement. The escapement-wheel had only three teeth, 
or, more properly, arms, and weighed 73 grains, about one-sixth of 
an ounce avoirdupois. After running six months, a three-legged//rae- 
^y-escapement was put in. This worked very well ; but, in 4852, a four- 
legged gravity-escapement was substituted for it, and retained until about 
1860, when the present double three-legged escapement was put in. It 
is, in all probability, the simplest and most complete escapement yet 
invented for giving regular force to the pendulm independent of the 
train. The pressure of the teeth, or arms, on the stops of the pallets is 
four ounces. In an ordinary dead-beat escapement, it would have been 
over four pounds. 
The whole pendulum weighs 680 pounds; its length is 14 feet 5 inches. 
The zinc compensation-tube is 10 feet 5 inches long, and is made of 
three tubes, one within the other, and drawn together until the thickness 
is half an inch. The center of gravity of the bob is about 8 inches below, 
the center of oscillation. Owing to the weight of the compensation- 32 
VIENNA INTERNATIONAL EXHIBITION, 1&73. 
tube, the pendulum-spring is 3 inches wide, 5 inches long between the 
chops, and one-sixtieth of an inch thick. 
To alter the clock less than four seconds, a collar is fixed on the pen- 
dulum 4 feet 10 inches from the top to carry the regulating weights. 
One and a half ounces placed there accelerate the pendulum one second 
a day. 
There is also a large weight of six pounds fitting around the pendu- 
lum, except on one side, so that it can be lifted off. If the clock is too 
fast, this weight is carefully removed while the clock is being w ound up, 
until it has lost the time desired-about a second in a quarter of an 
hour-and it is then put on again. If it is too slow, the clock may be 
accelerated by laying on another weight. 
There is no temperature-error, and no barometrical error can be dis- 
covered. The absence of the latter is owing, in some measure, to the 
fact that the pendulum swings through a larger arc than usual-2|° on 
each side of zero-and the circular error goes in an opposite direction 
to the barometrical error. 
The reports of the astronomer-royal show that its variation is less 
than one second a w7eek, and that it has been only 3 seconds wrong on 2 
per cent, of the days of observation. 
The clock reports its time to the observatory at Greenwich twice each 
day by electricity. Its rate is checked and recorded, and any error is 
telegraphed and corrected by the means before mentioned. 
The w7eekly variation of the Royal Exchange clock, which the astrono- 
mer-royal had at one time justly described as the finest clock in Europe, 
was four seconds, and that of one of Mr. Dent's best regulators two 
seconds. This is therefore a considerable advance in time-keeping. 
The dials consist of a cast-iron frame-work, forming the divisions and 
figures, filled with an expensive kind of opalescent glass; the minute- 
spaces are one foot square, and the figures two feet long. 
The center of the dials being 180 feet from the ground and illuminated 
at night, the time can always be seen at a long distance. Each of the 
four dials is 22| feet in diameter, of nearly 400 square feet area, and is, 
with the exception of one, having only an hour-hand, at the cathedral of 
Malines, the largest in the w orld. 
39. A complicated remontoir, with pin-wheel escapement, exhibited in 
a clock made by Haak Brothers, Rotterdam, seemed to have some good 
qualities. The wheels and other brass-wTork showed good workmanship, 
but nothing remarkable in construction. 
C. Weiss, of Posen, exhibited a large-sized movement with three, trains. 
Connected with the time-train was a spriug-remontoir of two wheels 
and Graham escapement, inclosed in a glass case. Twenty years ago 
such an arrangement might have met with favor; but simpler forms of 
construction are now preferred. 
There was a variety of escapements in the collection of J. Nehr, of 
Munich; some with double escapement-wheels, others with two pendu- 
lums, but none showing any practical advance in the art. TOWER CLOCKS. 
33 
J. Mannhardt, of Munich, has been awarded many medals for his pro- 
ductions. His clocks have cage-frames, and trains uniform in size ; they 
would do very well for places requiring small movements and no great 
accuracy in time-keeping. He uses the short wooden pendulum, with a 
rachet-wheel revolving on a pivot fastened near its point of suspension. 
A click fastened to the frame-work drops into the wheel and moves it 
one tooth forward at every vibration of the pendulum. When the wheel 
has made half a revolution, a pin on its side discharges the train, giving 
impulse to the pendulum, and moving the hands. It is probably better 
than the old dead-beat, but not equal to some modern gravity-escape- 
ments. 
Several clocks from Silesia had odd and heavy escapements, and were 
entirely behind the age. 
A few other makers from Germany and Austria exhibited specimens 
of their work; but, taking all the movements in the exhibition together, 
they were far from correctly representing the advanced state of turret- 
clock making at the present time. CHAPTER III. 
BALANCES AND MICROSCOPES. 
Balances ; Sensibility ; Exhibits ; Microscopes ; Recent improvements ; Exhi- 
bits; Amici's device. 
40. Balances.-Probably in no class of instruments have attempts 
to invent new forms or arrangements met with less success than in bal- 
ances used as instruments of precision. Being a very important, in 
fact, an indispensable, instrument to the analytical chemist and the 
assayer, the smallest improvement is a matter deserving notice. 
With regard to the great sensibility of some balances, as shown by 
the smallness of the weight required to turn the beam, but little more 
can be accomplished, as several makers have made them so delicate as 
to turn with jq pop qoo Paft of their load. One made by Saxton, and pre- 
sented by the Government of the United States to that of France in 
1851, indicated a difference of one unit in 20,000,000 in each pan. 
In order that a balance with a beam 20 inches long may indicate the 
one millionth part of its load, we must, at the most, have- 
1.000^00 = a-x or 10 inch 
1,000,001 a + x' ® = 2,000,000 
Within the same length, the two arms of the beam must be adjusted to 
equality, if the balance is to have the above degree of accuracy. As 
this length is not appreciable by the microscope, it will give some idea 
of the skill attained by the balance-maker in making his adjustments 
Any good balance should weigh with certainty to the XOO^OOO part of 
its load. Even the delicacy of such a balance is in advance of what may 
be required of it, as the result of few chemical operations can pretend 
t o an accuracy of i^,oOo part; therefore, it is the accessories facilitating 
the ease and rapidity with which accurate weighings may be made, 
which now more particularly require attention. 
41. Germany was represented by fifteen exhibitors. Among the most 
prominent were the following well-known makers: F. Hugershoff, of Leip- 
zig; A. Sauter, of Ebingen ; A. Oertling, of Berlin; Reimann, of Berlin ; 
Schickert, of Dresden ; Kern & Sons, of Oustmettingen ; and Staudinger, 
of Giessen. Only about one-third of the exhibitors presented balances 
showing good workmanship; although some of the others may have 
been adjusted to great accuracy. 
The balances that pleased us most were made by Hugershoff, of Leip- 
zig. They were unsurpassed in mechanical execution, judicious propor- 
tions, and attention to all the details required in making accurate 
adjustments. They had large pans, and beneath them an arrangement 
consisting of two large camel-hair brushes mounted upon the ends of 
levers; by means of these, the pans could readily be brought to a state 
of rest. BALANCES AND MICROSCOPES. 
35 
In the French department, Collot Brothers and E. Hardy, of Paris, 
exhibited some well-made balances. The latter claimed for a balance 
carrying 50 grams an accuracy of T|o- of a milligram. 
Although there are low-priced balances made in Europe giving good 
results, yet, in purchasing a first-class balance, when the custom-duty 
is added to the foreign article, it can probably be obtained of our own 
manufacturers as cheaply and as well made. 
42. Microscopes.-The success attending the efforts that have been 
made within the last thirty years in improving and perfecting the mi- 
croscope, so that it now gives clear and correct views of objects formerly 
deemed doubtful and unsatisfactory, has given a great impetus to micro 
scopical investigations, and enlarged greatly the number of enthusiastic 
workers in this fascinating branch of physical science. 
The display of these instruments in the exposition was almost entirely 
from Germany and France. None of England's celebrated makers were 
represented ; nor was our own country, whose opticians are well known 
for productions of the highest order, placed in a proper light in this con- 
cours of nations. 
43. The photographs of test-objects, taken through Dr. Hartnack's 
microscopes, were certainly remarkable specimens, showing the great 
perfection to which he has carried the art of making objectives with the 
four-system arrangement. The performance of his instruments fully 
sustained his widely-extended reputation for producing objectives of the 
highest order of excellence. 
Seibert & Kraft, of Wetzlar, made a display of excellent microscopes 
with accessory apparatus. After a thorough trial of their objectives, 
we can say that they deserve to be ranked with the best that are made, 
and the price, considering the quality, is the lowest that we have been 
able to find. Their No. V, equal to about an English one-sixth, has 
given them much reputation by its remarkable resolving powers upon 
the highest object-tests. Their objectives are admirably arranged as to 
angular aperture, so as to give the best working power to each objective 
in relation to the kind of work in which it is likely to be used. 
The mechanical execution and artistic proportions of their stands are 
unsurpassed, and the working arrangements are of the most satisfactory 
character. 
L. Beneche, of Berlin, also exhibited instruments of much merit. 
The good quality of his object-glasses has recently attracted consider- 
able attention, particularly his No. 7, which has given results deserving 
special notice. 
In the magnificent display of optical apparatus by G. & S. Merz, the 
successors of the renowned house of Fraunhofer, of Munich, were two 
microscopes of great merit. 
F. W. Schiek, the oldest maker in Berlin, exhibited some very good 
work at a moderate price. His stands and objectives somewhat resem- 
ble Dr. Hartnack's in appearance. 36 
VIENNA INTERNATIONAL EXHIBITION, 1873. 
Schmidt & Haensch, of Berlin, and R. Winkel, of Gottingen, also 
exhibited well-made microscopes and other optical apparatus. 
S. Plossel & Co., of Vienna, who have been making good microscopes 
for nearly thirty years, made a handsome display of optical instruments. 
A. Nachet, of Paris, displayed some of his best work. His latest large 
stand is somewhat complicated, but is admirably constructed. His stu- 
dent's microscope, whose chief peculiarity lies in its stage, has been 
acknowledged by the best authorities to be the most perfect of its kind 
that has ever been devised. The quality and price of his instruments 
are so well known as to scarcely require mention. 
C. Verick, of Paris, a pupil of Hartnack, exhibited some fine object- 
ives. His stands resemble, very much in construction those of Dr. 
Hartnack, and his work in general has considerable merit. 
44. The immersion-principle, first devised by Amici for high powers, has 
very much increased the usefulness of objectives, and is now adopted 
by all the best makers. It has been applied with such success to powers 
as low as one-sixths with high angular apertures, that they have lately 
been made to resolve the lines on the A. peilucida, which are about 
92,000 to the inch. These objectives are sometimes supplied with dry 
fronts, and others will work either wet or dry by corrections made with 
a screw-collar. 
Comparatively low powers, with wide angular apertures, can now be 
made to do the work for which the highest that can be constructed have 
been supposed to be necessary. One-eighths have recently been made, 
which, with deep eye-pieces amplifying 2,000 times, give views of P. 
angulatum surpassing in beauty and brilliancy any ever seen before. 
Some opticians are working on a plan precisely opposite to the above, 
by reducing the angular aperture, securing great working distance and 
penetration, and yet obtaining an amount of resolving power hitherto 
supposed to be exclusively the property of far larger-angled glasses. 
One-sixths, with an angular aperture of 68°, have been made that give 
admirable definition of P. hippocampus, and show the transverse mark- 
ings on & gemma resolved into beads, showing how much more than has 
been expected can be done on the plan of a small angle and great work- 
ing distance. Even one-fourths, with 48° angular aperture, have been 
made so perfect as to work well with deep eye-pieces. 
Amid the great variety of object-glasses that are now made, the 
microscopist has a wide range for making a selection in adapting his in- 
strument to the kind of work in which he may be making his investiga- 
tions; and, unless some new principles be discovered, microscope-making 
has about reached its limit of perfection. The very low price at which 
the best German instrument, which will rank with any that are made, 
can be purchased will now enable them to reach the hands of persons of 
moderate means, and thus largely to increase the number of investiga- 
tors in the beautiful science of microscopy. IND EX. 
Art. Page. 
Accuracy of chronometers 6 8 
American clocks 34 27 
Amici's invention 44 36 
Audemar's exhibit 21 16 
Austrian exhibits 32 23 
watch-work 27 20 
Awards at trial of watches 20 15 
Badollet & Co.'s exhibit 18 14 
Balances, sensibility of 40 34 
Balance-spring, value of 13 12 
Bavarian exhibits 32 23 
Breguet's exhibit 23 17 
report on cheap watches 24 18 
Chronometers, accuracy of 6 8 
American market for 14 12 
British exhibit 8 9 
other foreign exhibits 9 10 
Harrison's 3 7 
history of 3 7 
Hooke's improvement 4 7 
isochronism of 5 8 
records of trials of 7 9 
Clocks, American 34 27 
Austrian , 32 23 
Bavarian 32 24 
Dutch 33 25 
electrical 35 26 
French 33 26 
history of 30 22 
peculiarities 31 23 
tower 36 28 
Westminster tower 38 30 
Dutch clocks 33 25 
English watches 25 19 
Electrical clocks 35 27 
Escapement, tourbillon 16 13 
French clocks 33 25 
German exhibits 26 19 
Greenwich Observatory records 7 9 
Harrison's chronometer 3 
History of chronometers 3 
clocks 30 22 
Hooke's improvement 4 
Horology, schools of 15 13 
Dr. Hooke's w-wk in 4 7 
Isochronism in chronometers 3 7 
Jaccard's exhibit - 22 16 
Labor-saving machinery 2 5 
Machinery, labor-saving 2 5 38 
Art. Page. 
Microscropes, Amici's improvement in 44 36 
Exhibit of 43 35 
Recent advances 42 . 35 
Montandon's exhibits 22 16 
Observatory trials of watches 19 15 
Patek, Philippe & Co.'s exhibit of watches 17 14 
Peculiarities of the tower-clock 37 28 
Position, compensation for temperature and 11 11 
Report on cheap watches, by Breguet 21 18 
Schools of horology and their work 15 13 
Strikes 2 5 
Swiss clocks 33 25 
watches 12 12 
Temperature and position, compensation for 11 11 
Tests of watches at observatories 19 15 
Tourbillon escapements 16 13 
Tower-clocks r ........... 36 28 
peculiarities of . 37 28 
Patek, Philippe & Co.'s 17 14 
Watches, Austrian ; 27 20 
Badollet & Co.'s. 18 14 
Breguet's report on cheap 24 18 
compensation of 11 11 
English . 25 19 
German 26 19 
improvements in 20 20 
Patek, Philippe & Co.'s 17 14 
pocket-chronometers and 10 10 
Swiss and English, compared 12 12 
tests at the observatories 19 15 
INDEX.