TENANT HOUSES. 
BY 
WM. F. THOMS, M. I). TENANT HOUSES: 
THEIR 
GROUND AREA, CUBIC FEET OF AIR SPACE, AND VENTILATION. 
BY 
WM. F. THOMS, M. D., 
SURGEON TO THE EASTERN DISPENSARY; PHYSICIAN TO THE 
NEW YORK DISPENSARY; PHYSICIAN AND SURGEON 
TO THE HOWARD MISSION. 
Reprinted from the Transactions of the N. Y. State Medical Society for 1867. 
ALBANY: 
VAN BENTHUYSEN & SONS’ STEAM PRINTING HOUSE. 
1867. TENANT HOUSES. 
In the preparation of this paper, the most practical works on 
hygiene have been consulted, consisting of Dr. Parke’s Manuel on 
Practical Hygiene, the sanitary condition of New York, etc., etc. 
I am greatly indebted to Dr. Hampton Harriot, of the New York 
Dispensary, for valuable suggestions in relation to the subject of 
ventilation. 
According to the most accurate statistics collected in 1863 by 
Capt. Lord of the sanitary squad of the metropolitan police, there 
were 15,369 tenant houses in the city of New York (the number 
is rapidly increasing), containing a population of about 500,000. 
Most of the houses are overcrowded, their ground-area and cubic 
feet of air space much too small, and the ventilation very imper- 
fect, the sleeping rooms in many instances have not the slightest 
circulation of air in them, thus increasing the number and severity 
of the zymotic (or foul air) disease.* 
The most marked feature of the tenant houses is the small size 
of their apartments, whereby ensues overcrowding in each family. 
* Death-rate from zymotic diseases (foul air diseases) in England, London and New 
York, extracted from my paper on health in country, and cities, published in the Trans- 
actions of the American Medical Association : 
In England. 
In London. 
In New York. 
Death. Pop. 
Death. Pop. 
Death. Pop. 
Small pox 
3,413 
1 in 
1,384 
1 in 
1,303 
Measles 
1,790 
1 in 
1,772 
1 in 
4,186 
Scarlatina 
669 
1 in 
585 
1 in 
996 
Diphtheria 
3,125 
1 in 
3,755 
1 in 
918 
Quinsey. 
62,500 
1 in 
35,802 
] in 
81,818 
Croup 
2,024 
1 in 
3,111 
1 in' 
901 
Whooping cough 
1,805 
1 in 
1,333 
1 in 
7,087 
Typhus and typhoid fever 
1,129 
1 in 
1,032 
1 in 
854 
Erysipelas 
10,034 
1 in 
6,561 • 
1 in 
7,258 
Metritis (puerperal fever) 
17,561 
1 in 
13,181 
1 in 
10,742 
Carbuncle 
83,333 
1 in 
51,786 
1 in 
250,000 
Influenza 
22,223 
1 in 
70,732 
1 in 
81,818 
Dysentery 
19,281 
1 in 
26,851 
1 in 
3,146 
Diarrhoea 
1,361 
1 in 
1,212 
1 in 
380 
Cholera 
25,000 
1 in 
18,230 
1 in 
7,429 
Ague 
142,830 
1 in 
152,681 
1 in 
56,250 
Remittent fever 
100,000 
1 in 
32,954 
l in 
34,615 
Rheumatism 
9,346 
1 in 
6,666 
1 in 
18,544 
Other zymotic diseases. 
166,666 
1 in 
116,000 
1 in 
150,000 4 
The common mode of arranging them is as follows: (See draw- 
ings No. 1 and 2.) 
On a lot of ordinary size, twenty-five by 100 feet, will be erect- 
ed a front house twenty-five by fifty, and a rear house twenty-five 
by twenty-five, with a court twenty-five by twenty-five, and frequent- 
ly less, in which are located hydrant, cesspool and privy. These 
houses are commonly five and frequently six stories in height 
above the basement, the principal rooms of which there are four to 
each floor, occupy the width of the building front and rear, 
with small bed-rooms between, one to each main room. This 
arrangement gives accommodation to four families on each floor, 
making in a six story building twenty-four families, each family 
averages five members, aid frequently more, as it is common for 
the occupants of these houses to take lodgers. 
In this arrangement each person has a little over fifteen square 
feet in ground area, and 480 cubic feet of air space in the whole 
house. In the apartments the allowance of air space is 317 cubic 
feet, and in the dormitories but 89 feet to each person. This is 
the average, but there are many exceptions where the over-crowd- 
ing far exceeds this. In addition the facilities for ventilating these 
small apartments are wholly confined to doors and windows, hall, 
ways and passages are dark and narrow, and the house is often 
surrounded by others of greater height, shutting out the cheerful 
and health-giving influences of sunlight and air. 
The arrangement of tenant houses from street to street is as fol- 
lows (see drawing No. 3): Front house, court, rear house, small 
space between the rear houses, in which filth of all kinds accumu- 
late, rear house, court and front house. 
GROUND AREA. 
Each person should have at least 50 superficial or square feet. 
(See drawing No. 4.)* This would allow 50 persons to each lot 
25 by 100 feet. This arrangement would be the most practicable 
means of preventing over-crowding. The present average ground 
area is 15 square feet. (See drawing No. 5.) 
* In the metropolitan lodging houses 30 superficial and 240 cubic feet are allowed; in 
the section houses of the metropolitan police 50 feet superficial and 450 cubic feet are given. 
The poor-law hoard allow 300 cubic feet for every healthy person in dormitories, and 500 
cubic feet for sick persons. In Dublin an allowance of 300 cubic feet is required in the 
registered lodging houses.—From, an excellent Pamphlet entitled “ Essentia's of a Healthy 
Dwelling.” Rule. 
Each person should have 50 superficial or square feet of ground- 
area. 
Cubic Feet of Air Space. 
The following drawings illustrate the amount of air space which 
should be allowed to each person, compared with the average air 
space at present in tenant houses. 
The standard amount of air space which practical hygienists 
say is necessary, is 1,000 cubic feet to each individual (see drawing 
No. 6); but this is too large an amount to be made practical in 
our tenant houses, therefore, I have placed the amount at 700 
cubic feet of air space to each person—(see drawing No. 7)—it 
should never be less. This amount, with proper ventilation, will 
be sufficient to enable the human system to perform its functions 
properly. 
The average amount at present in tenant houses is about 480 
cubic feet (see drawing No. 8), but in many of them it is much less.* 
The standard air space for the apartments should be 500 cubic 
feet. (See drawing No. 9.) 
The present average in the apartments in tenant houses is about 
300 cubic feet. (See drawing No. 10.) 
The standard air space for dormitories (sleeping rooms) should 
be 300 cubic feet. (See drawing No. 11.) 
The present average in sleeping rooms is about 89 cubic feet. 
(See drawing No. 12.) 
Kule. 
Every tenant house should have 700 cubic feet of air space to 
each person. The apartments 500 cubic feet, and the dormitories 
300 cubic feet. 
* The following is an extract from Capt. Lord’s report, illustrating this point 
Tenant Houses. 
Haring from 
Cubic feet to 
each person. 
No. of 
houses. 
289 
1,198 
2,125 
2,742 
2,465 
2,028 
2,221 
2,241 
Popu- 
lation. 
9,642 
44,989 
77,894 
96,828 
79,237 
60,215 
60,682 
50,845 
700 to 800 
15,309 
480,368 
Cellar population 
Grand total 
15,224 
495,592 6 
Quantity of Aiii. 
What quantity of air must be supplied per head per hour, so as 
to dilute the products of respiration and transpiration from the 
healthy body, so as to keep the air always pure and fresh f 
For healthy adult men, the question may be answered both by 
calculation and experiment. Taking the carbonic acid of respira- 
tion as a convenient measure of impurity, the following table will 
show the mode of calculation: 
1. An adult man inspires and expires, on an average, 30 cubic 
inches at every respiration, and he breathes 16 times per minute. 
30 by 16=480 cubic inches. 
2. In an hour he therefore expires—480 by 60=28,800 cubic 
inches, or 16.66 cubic feet. . 
3. The air he breathes in (if pure) contains 0.4 per 1,000 vol- 
umes of carbonic acid, while the air he breathes out contains 40 
volumes per 1,000 of carbonic acid, in addition to foetid organic 
matter undetermined in amount, and watery vapor to saturation; 
or in other words, about 0.5 or 0.6 cubic feet of carbonic acid, and 
136 grains of watery vapour, are eliminated per hour, or from 12 
to 16 cubic feet of carbonic acid in 24 hours. 
4. To dilute the expired air, so that the amount of carbonic acid 
shall be reduced to 0.4 per 1,000, more than 100 times the volume 
of expired air must be supplied per hour. 16.66 by 100=1,666 
cubic feet. 
5. But as the added air contains some carbonic acid, and as the 
exhalations from the skin require to be also diluted, at least one- 
fourth more must be added, which brings up the amount to 2,082 
cubic feet per hour. 
Pettenkofer,* by a similar calculation, has fixed the amount as 
200 times the volume of the expired air, which he puts at 300 
litre (=10.6 cubic feet per hour). Veerodit’s calculation of the 
expired air is 12.75 cubic feet, and Valentin’s 16.6 cubic feet per 
hour. Practical experience confirms this result. 
The successive experiments made by Grassi and others have 
shown, first, that allowances successively given of 10 cubic metres 
(=353 cubic feet), of 20 cubic metres (706 cubic feet), of 30 cubic 
metres (1,059 cubic feet), were quite insufficient for one man, and 
the quantity was gradually increased till 60 cubic metres (2,118 
cubic feet) were given. The air in the cell of a prisoner who 
received that ration of air seemed pure to the senses. 
* Meber den Luftweehsel von Dr. Yon Max Pettenkofor, 1858, p. 85. From a number of experiments in which the outflow of air was 
measured and the carbonic acid simultaneously determined, it has 
been found by Dr. Parkes that at least 2,000 cubic feet per hour 
must be given to keep the carbonic acid at 0.5 or 0.6 per 1,000 
volumes, and to entirely remove the foetid smell of organic matter. 
When 1,200 or 1,400 feet only were given, the carbonic acid 
amounted to 0.7, 0.8, or 0.9 per 1,000 volumes, and the organic 
matter was in sufficient amount to destroy .00002 grammes of per- 
manganate of potash, when 12 cubic feet of air were drawn through. 
Air Vitiated by Respiration. 
The carbonic acid of respiration is equally diffused through the 
air of the room; it is very rapidly got rid of by opening windows, 
and in this respect differs from the organic matter, and probably 
from the watery vapor; neither appear to diffuse rapidly or 
equally through a room. By the skin and lungs, pass off from 25 
to 40 ounces of water in 24 hours, to maintain which, in a state 
of vapor 211 cubic feet of air per hour is necessary on an aver- 
age. Of course, however, temperature and the hygrometric con- 
dition of the air greatly modify this. 
Organic matter is also given off, the amount of which has never 
been precisely determined, and has been variously estimated at 
from 10 to 240 grains. Perhaps at present it may be approxi- 
mately stated at 30 grains per diem for each adult. This organic 
matter must be partly suspended, and is made up of small parti- 
cles of epithelium and fatty matters, detached from the skin, and 
partly of an organic vapor, given off from the lungs and mouth. 
The organic matter from the lungs when drawn through sulphuric 
acid, darkens it; through permanganate of potash, decolorizes it, 
and through pure water, renders it very offensive. Collected from 
the air by condensing the watery vapor on the sides of a globe 
containing ice, it is found to be precepitated by nitrate of silver, 
to blacken on platinum, and to yield ammonia; it is, therefore, 
nitrogenous. It has a foetid smell, and this is retained in a room 
for so long a time, sometimes for four hours, even when there is 
free ventilation, as to show it is oxydized slowly. It is probably 
in combination with water, for the most hygroscopic substances 
absorb most of it. It is absorbed most by wool, feathers, damp 
walls and moist paper, and least by straw and horse hair. The 
color of the substance, influences its absorption in the following 
order;—black most, then blue, yellow and white. It is probably 8 
not a gas, but is molecular, and floats in clouds in the air, as the 
odor is evidently not always equally diffused through a room. 
This quantity is in no very close relation to the carbonic acid, 
though a large quantity of carbonic acid derived from respiration 
always indicates a large quantity of organic matter. In a room, 
the air of which is at first perfectly pure, but is vitiated by respi- 
ration, the smell of organic matter is generally perceptible when 
the carbonic acid reaches 0.7 per 1,000 volumes, and is very 
strong wrhen the carbonic acid amounts to 1 per 1,000. Various 
experiments have shown that the amount of potassium destroyed 
by air drawn through its solution, is generally in proportion to 
the amount of carbonic acid of respiration. 
Assuming that the organic matter has an effect on the perman- 
ganate of potash equal to that which sugar has, DeAngus Smith 
has calculated the amount of organic matter to be, 
Cubic feet of air. 
In a bed-room one grain in „ 64,000 
In a bed-room one grain in 56,000 
Inside a house 16,000 
In a closely packed railway carriage i 8,000 
When the air of a sewer entered a house 8,000 
Ash of midden or cesspool 62 
Pure air on high ground v 170,000 
Pure air on high ground 209 000 
Besides the gaseous products strictly derived from the lungs, 
the air of most dwelling houses, when examined by the aeroscope 
is found to contain many epithelium cells; many of them are 
evidently derived from the skin; they are rubbed off, and then float 
through the air. Some of the cells are smaller and rounded, and 
are either nuclei, or are from some parts of the air-tubes. Frag- 
ments of cotton fibre, wool, etc., etc., are also found. The plates 
show some of these objects found by Messrs. Hawlett, Stanley 
and Reed in the barracks at Gravesend. (See drawing No. 13.) 
In all tainted atmosphere of this kind, it would appear that the 
germ of infusoria abound to a much greater extent than in pure 
air. It seems probable that the discovery of suspended matters 
of this kind will lead to most important results. The possibility 
of a direct transferrence from body to body of cells undergoing 
special changes is thus placed beyond doubt, and the doctrine of 
contagion receives an additional elucidation. It remains to be seen 
whether pus and epithelium cells becoming dried in the atmos- 9 
phere can again on exposure to warmth and moisture, undergo 
the chemical changes which have been interrupted, or whether 
they would not rather break down into impalpable particles, and 
be then totally oxydized and destroyed. It is now generally 
admitted that protophytes like the prolococcus pluvialis, may be 
dried and yet retain their vitality even for years, and may be 
blown about in atmospheric currents, but it would not be right to 
infer a similar power on the part of epithelium or pus cells. 
Effects of Impure Air. 
The effect of the foetid air containing organic matter, excess of 
water and carbonic acid, produced by respiration, is very marked 
upon many people; heaviness, headache, inertness, and in some 
cases nausea, is produced. From experiments on animals in an 
atmosphere from which carbonic acid and watery vapor were 
removed, and organic matter alone left, Cavarret and Hammond 
have found that the organic matter is highly poisonous. 
Hammond found that a mouse died in 45 minutes, and Dr. 
Parkes has known cases in which the inhalation of such an atmos- 
phere for three or four hours produced in men decided febrile 
symptoms (increased temperature, quickened pulse, furred tongue, 
loss of appetite and thirst), for even 24 or 48 hours subsequently. 
When the air is rendered still more impure than this, it is 
rapidly fatal, as in the case of the Black Hole of Calcutta, of the 
prison in which 300 Austrians were placed after the battle of 
Austerlitz (when 200 died very rapidly). The poisonous agencies 
are probably the organic matter and the deficient oxygen, as the 
symptoms are not those of pure asphyxia. If persons survive, a 
febrile condition is left behind which lasts them three or four 
days, or there are other evidences of aflected nutrition, such as 
boils, &c. 
When air more moderately vitiated by respiration is breathed 
for a longer period, and more continuously, its efiects become 
complicated with those of other conditions. Usually a person who 
is compelled to breathe such an atmosphere is at the same time 
sedentary, and perhaps remains in a constrained position for seve- 
ral hours, or possibly, is also under-fed or intemperate.* But 
* The following table shows the well known fact that the liquor stores are more nume- 
rous in those parts of the city of New York where the tenant-house population is the 
greatest. 
The people being deprived of the natural stimulus of pure air, and having to live in foul 
[Akt. 19.] 10 
allowing the fullest effect to all other agencies, there is no doubt 
that breathing the vitiated atmosphere of respired air has a most 
injurious effect on health. Persons soon become pale, and par- 
tially lose their appetite, and after a time decline in muscular 
strength and spirits. 
The aeration and nutrition of the blood seems to be interfered 
with, and the general tone of the system falls below par, so that 
there appears to be less resistance to the action of morbific causes. 
Of special diseases it appears pretty clear that pulmonary affec- 
tions are more common. * 
Those persons who live in confined quarters do certainly appear 
to furnish a most undue percentage of phthisical cases. The pro- 
duction of phthisis from impure air (aided most potently, as it 
often is, by co-incident conditions of want of exercise, want of 
good food and excessive work), is no new doctrine. Baudelocque 
air, are compelled, to resort to artificial stimulation to maintain their drooping spirits, until 
the powers of life are exhausted. Can happiness or comfort be obtained under such 
circumstances ? 
Wards. 
Total 
population. 
Tenant 
house 
population. 
Liquor 
stores. 
Proportion 
to total 
population. 
1 
9,062 | 
276 
1 to 75 
2 
2,507 
3 
1,305 > 
476 
1 to 55 
5 
22'341 
11,206 \ 
4 
17,957 
22,897 
465 
462 
1 to 47 
1 to 57 
1 to 150 
1 to 80 
1 to 126 
6 
26'694 
7 
20,526 
266 
8 
16,888 
15,172 
500 
350 
9 
10 
18,583 
510 
1 to 57 
1 to 126 
1 to 174 
1 to 94 
11 
65,620 
475 
176 
350 
12 
30,647 
13 
32,914 
15,936 
14 
28,087 
20,425 
437 
210 
1 to 64 
1 to 131 
15 
5^205 
16 
33,650 
309 
1 to 146 
17 
66^207 
438 
1 to 166 
18 
57,464 
36^099 
401 
1 to 143 
19 
32,841 
16,272 
350 
1 to 93 
20 
33^218 
458 
1 to 163 
21 
36', 870 
300 
1 to 163 
22 
32,'644 
375 
1 to 164 
* The following extract from my paper on health in country and cities (Prize Essay), pub- 
lished in the Transactions of the American Medical Association, show the comparative pre- 
valence of pulmonary affections in England, London and New York : 
England. 
London. 
New York. 
Death. 
Pop. 
Death. Pop. 
Death. Pop. 
398 
1 in 369 
1 in 253 
635 
1 in 483 
Pleurisy 
Pneumonia 
1 in 18,954 
1 in 788 
1 in 7,085 
1 in 519 
As might have been expected, the death-rate is much greater in New York than in Eng- 
land or London, from the want of pure air in the tenant houses. 11 
long ago asserted that impure air is the great cause of scrofula 
(phthisis), and that hereditary predisposition, syphilis, unclean- 
ness, want of clothing, bad food and humid air, are by themselves 
non-effective. Carmichael, in his work on scrofula (1810), gives 
some most striking instances, where impure air, bad diet, and 
deficient exercise concurred to produce a most formidable mor- 
tality from phthisis. In one instance, in the Dublin house of 
industry, where phthisis was formerly so common as to be thought 
contagious, there were in one ward 60 feet long and 18 feet broad 
(height not given), 38 beds, each one containing four children ; 
the atmosphere was so bad that in the morning the air in the ward 
was unendurable. In some of the schools examined by Carmichael 
the diet was excellent, and the only causes for the excessive prev- 
alence of phthisis were the foul air, and want of exercise. This 
was also the case in the house and school examined by Neil 
Arnott in 1832. 
In the prison of Leopoldstadt at Vienna, which was very badly 
ventilated, there died in the year (1834-1847) 378 out of 4,280 
prisoners, or one in twelve, and of these no less than 220, or one 
in nineteen died from phthisis. There were no less than 42 cases 
of acute miliary tuberculosis. In the well ventilated house of 
corrections in the same city there were in five years (1850-1854) 
3,037 prisoners, of whom 43 died, or one in seventy-one, and of 
these 24, or one in 126 died of phthisis. 
The most important class of diseases produced by impurities in 
the atmosphere are certainly caused by the presence of organic 
matter floating in the air, since under this heading come all the 
specific diseases. The exact condition of the organic matter is 
unknown; whether it is in the form of impalpable particles, or 
moist or dried epithelium and pus cells, is a point for future 
inquiry; and whether it is always contained in the substances dis- 
charged or thrown off from the body, (as is certainly the case in 
small-pox,) or is produced by putrefactive changes in those 
discharges, as is supposed to be the case in cholera and dysentery 
is also a matter of doubt. But from the way in which, in many 
cases, organic substances are absorbed by hygroscopic substances, 
it would appear that it is often combined with, or is at any rate, 
condensed with the water of the atmosphere. 
The specific poisons manifestly differ in the case in which they 
are oxydized and destroyed. The poison of typhus exanthematicus 
is very readily got rid of by free ventilation, by means of which 12 
it must be at once diluted and oxydized, so that a few feet give, 
under such circumstances sufficient protection. This is the case 
also with the poison of oriental plague; while on the other hand, 
the poisons of small-pox and scarlet fever will spread in spite of 
very free ventilation, and retain their power of causing the same 
disease for a long time, even it may be for weeks, or in the case 
of scarlet fever, for months. 
Is it that in the one case the poison is a mere cloud of molecules; 
that in the other it is contained in epithelium and pus cells thrown 
off (from the skin in both cases; and from the throat also in one, 
and which adhering to walls, clothing, &c., partially dry, and then 
can be rendered again active by warmth and moisture? 
The same evidence of the effect of pure and impure air on 
health and mortality is still more strikingly shown by horses; for 
in that case the question is more simple on account of the absolute 
similarity in different periods or places of food, water, exercise 
and treatment. Formerly in the French army, the mortality 
among the horses was enormous. Rossignol states that previous 
to 1836, the mortality of the French cavalry horses varied from 
one in six to one in five per annum. The enlargement of the 
stables and the increased quantity of the ration of air, reduced 
the loss in the next ten years to one in fifteen. 
In the English cavalry (and in English racing stables) the same 
facts are well known. Wilkinson informs us that the annual 
mortality of cavalry (which was formerly great) is now reduced 
to 1 in 50, of which one-half is from accidents and incurable 
diseases. Glanders and Farcy have almost disappeared, and if a 
case occurs, it is considered evidence of neglect. 
The food, exercise and general treatment being the same, this 
result has been obtained by cleanliness, dryness and the freest 
ventilation. The ventilation is threefold—general ventilation, for 
drying the floors, ceiling ventilation, for discharge of foul air, 
and supply of air beneath the horses’ noses, to dilute at once the 
products of respiration. In cow houses and kennels, similar facts 
are well known; disease and health are in the direct proportion 
of foul and pure air. That the breathing of air rendered impure 
from any cause is hurtful, and the highest degree of health is only 
possible, when to other favorable conditions is added that of a 
proper supply of pure air, might be inferred from the physiolo- 
gical evidence of the paramount importance of proper aeration of 
the blood. Experience strengthens this inference. Statistical 13 
inquiries on mortality prove beyond a doubt that of the causes of 
death wThich usually are in action, impurity of the air is the most 
important. Individual observation conflrms this. No one who 
has paid any attention to the condition of health, and the recovery 
from disease of those persons who fall under his observation, can 
doubt that impurity of the air marvellously affects the first, and 
influences and sometimes even regulates the second. The average 
mortality in England increases tolerably regularly with density of 
population. Density of population usually implies poverty and 
insufficient food, and unhealthy work, but its concomitant condition 
is impurity of air from overcrowding,* deficiency of cleanliness, 
and imperfect removal of excreta, and when this condition is 
removed, a very dense and poor population may be perfectly 
healthy. 
Ventilation. 
In order to keep air in its necessary purity, it must be continu- 
ally changing. 
We have already seen that the change must amount to at least 
2,000 cubic feet per hour per head for persons in health, and 
double that quantity for sick persons. 
In whatever way this air is supplied, certain conditions must be 
laid down. 
The entering air: First. The air which enters must itself be pure. 
Second. Its movement should be imperceptible, otherwise it will 
cause the sensation of draught, and will chill. 
The rate at which the movement becomes imperceptible is much 
influenced by the temperature of the air. If this is above 70° 
•See Dr. Duncan’s evidence in the Health of Towns Report, vol. 1, p. 131. On this 
point Dr. Gairdner has also brought together some good evidence in his work on “Public 
Health in relation to Air and Water,” p. 52, et seq. 
The following part of his table may be quoted : 
Population to one square mile in 
districts taken in England. 
56 
Death per 1,000 
per annum. 
Death-rate. 
Death. Pop. 
1 in 67 
106 
16 
1 in 63 
144 
1 in 60 
149 
18 
1 in 56 
1 in 53 
$02 
1 in 50 
220 
21 
1 in 48 
324 ..... 
1 in 46 
485 t,,, 
1 in 44 
13 216 
24 
1 in 42 
1 j262 
25 
1 in 40 
1 in 39 
2,900 
1 in 67 14 
a very considerable velocity is not perceived. But taking the 
temperature of 55° or 60°, a rate of \\ per second (one mile 
per hour) is not perceived; a rate of two or 2-| feet per second (1| 
and miles per hour) is imperceptible to some persons; three 
feet per second (two miles per hour nearly) is perceptable to 
most; a rate of 3-| feet is perceived by all persons. Any greater 
speed than this will give the sensation of draught, especially if the 
entering air be of a different temperature or moist. 
Third. It must be well diffused through the room, so that 
in every part movement shall be going on; in other words, the 
distribution must be perfect. 
The out going air: Fourth. The air must be removed so im- 
mediately that their shall be no risk of a person breathing again 
his own expired air, or that of another person. 
There is a difference of opinion in regard to the comparative 
value of the upward and downward system of ventilation. Both 
have their advantages and disadvantages, and their comparative 
merits can only be decided by practical observation made by 
numerous observers. 
In the ventilation of the rooms in tenant houses, it is my opinion 
that the downward system is the most practical. (See drawings 
Nos. 14, 15 and 16.) 
First. On account of the diffusion of air being more uniform and 
there being less danger of a draught. 
Second. The saving of heat, which is an important item to the 
inhabitants of these houses. 
Third. Less danger of their being interfered with, the cold air en- 
tering by the grating at the roof of the room being brought in contact 
with the warm air before it descends, becomes warm, and not impart- 
ing the sensation of chilliness. The attention of the inmates is not 
directed to the source of fresh air, and there is less danger of the 
openings being obstructed. The foul air openings being near the 
floor are connected with the chimney, or a shaft adjoining the flues. 
The heat from the stove and chimney draws the foul air out of the 
apartments. The stoves in these houses are used constantly both 
summer and winter. The air passing through the outlet being 
warm does not call the attention of the inmates to it, therefore it 
is not interfered with. 
In the halls and stairways the upward system of ventilation is 
the best, (see drawings No. 17), the air entering by the street 
door, passes through the halls and stairways to the roof, and 15 
escapes through the ventilators or skylight; thus keeping a con- 
stant circulation of air through the center of the house. 
Size of the Openings, whether intended for Inlets or Outlets. 
As the movements of air increases with temperature, the size of 
the aperture can only be fixed for a certain given temperature ; 
and as the efilux of hot air increases with the column (supposing 
the temperature is equal) throughout, a different size has also to 
be arranged for different heights. 
Supposing that the height of the heated column be fifteen feet, 
a difference of ten degrees between the external and internal air 
produces an efflux (allowance being made for friction), of about 
12,000 linear feet per hour. For an opening of one square foot 
12,000 cubic feet would, therefore, be discharged ; and if the dis- 
charge per man is to be 2,000 cubic feet per hour, the share of 
outlet space per man will be, of course, the sixth part of a square 
foot, or 24 square inches. This is nearly equivalent to a square 
opening five inches (49 inches) to the side. There must be, of 
course, an equal amount of inlet, so that the inlet and outlet 
together would be 48 square inches per head. This, therefore, 
would be the total open area necessary for each person, independ- 
ent of all openings by windows and doors. 
The apartments occupied by each family should have an inlet 
for fresh air consisting of a tube one foot square, (which will allow 
1,200 cubic feet of air to pass through it every hour), extending 
from the front of the house to the sleeping rooms, also an outlet 
for the foul air, one foot square, in the chimney near the floor. 
The top of the chimney to be supplied with a cowl (ventilator), 
turning away from the wind, in order to have the full effect of 
the aspiratory power of the wind, and prevent down draughts. 
The roof over the stairway and halls should be furnished with 
a skylight the whole length and breadth of the upper hall; the 
top of the skylight should be provided with two large cowls 
(ventilators), one at each end. 
Rule. 
Explanation of Drawings Illustrating the Proposed System 
of Ventilation in Tenant Houses. 
The first three drawings illustrates the downward system of 
ventilation, the air enters the ventilator between the two windows 
and passes through the tube, up to the roof of the room ; it is 16 
then carried through the living room into the sleeping room (the 
curve in the tube preventing the warm air from escaping through 
this opening.) The sleeping rooms are in many instances without 
windows or ventilators of any kind ; it is here that the noxious 
gases from respiration and transpiration accumulate, causing so 
much sickness and death among the inhabitants of these houses. 
The air, after circulating through these rooms, passes into the 
living room, then through the foul air opening up the chimney, 
thereby keeping up the circulation through the rooms without the 
loss of much heat. The air entering by the roof becoming warm 
before it comes in contact with the inmates of the room, does not 
give that sense of chilliness which is felt when the upward system 
of ventilation is employed. 
The last drawing represents the upward system of ventilation, 
which is the best one for the ventilation of halls and stairways ; 
the air entering by the street door passes up the stairway and 
through the halls to the roof, and escapes through the ventilator 
or skylight. 
The following is a plan for collecting information in regard to 
the population, ground-area, cubic feet of air space, ventilation, con- 
dition of the atmosphere, etc., in tenant houses. 
The practical consideration of this subject is of great importance, 
and should enlist the active energies of this society, and of all who 
have the welfare of the human race at heart. 
The observations and remarks in this paper are merely pre- 
liminary to a more extended study of this subject. 
Hoping this paper will be the means of calling your attention 
to this great field of research, so that by united efforts we may be 
able to collect accurate information, which, properly arranged and 
systematised, will be the means of making practical sanitary science 
the greatest boon which Medical men have given to the world 
during this century. Plan for the examination )f tenant houses in regard to their population, ground area, cubic feet of air-space and 
ventilation. 
WARD. 
STREET. 
Number 
of families. 
Number 
of persons. 
DIMENSIONS OF LOT. 
DIMENSIONS OF HOUSE. 
No. 
Name. 
F. | R. 
Length. 
Breadth. 
Square 
feet. 
Length. 
Breadth. 
Number 
of stories. 
Ileighth 
of floors. 
Cubic 
feet. 
1 
| 
WARD. 
DIMENSIONS OF LIVING ROOM. 
DIMENSIONS OF SLEEPING ROOMS. 
Ground 
area in sq. 
feet. 
CUBIC FT. OF AIR SPACE. 
Length. 
Breadth. 
Ileighth. 
Cubic! Number 
feet. ! of inmates. 
Length. 
Breadth. 
Ileighth. 
Cubic 
feet. 
Number 
of inmates. 
In 
house. 
In living 
rooms. 
In sleeping 
rooms. 
1 
| 
| 
[Art. 19.] WARD. 
VENTILATION. 
By doors. 
By windows. 
By chimney. 
By special 
openings. 
MOVEMENT OP AIR IN THE ROOM. 
Direction of 
RATE OP MOVEMENT. 
By the ane- 
mometer. 
By the man- 
ometer. 
By calculation. 
WARDS. 
EXAMINATION OP THE AIR. 
Remarks. 
By the senses. 
MICROSCOPICAL AND CHEMICAL. 
The existence and 
nature of suspen- 
ded matters. 
The amount of organic 
matters, as estimated 
by permanganate of 
potash. 
The amount of 
carbonic acid. 
The amount of 
watery vapor. 
The presence of ammo- 
nia and sulphuretted 
hydrogen. 
Plan for the examination of tenant houses, etc.—Continued.