which, added to the natural ventilation produced by the kitchen fire, will fully suffice to change the air of such a kitchen more than once an hour.

The expense for a whole year for one small gas-burner, consuming 11⁄2 feet of gas an hour, and burning six hours a day, would be 84 cubic feet a day, or 3,100 cubic feet a year, which, at the rate of $1.70 a thou'sand feet, would cost $5.27, a very moderate expenditure for getting rid of a nauseous smell, which would otherwise be experienced twice a day.

It may be added that the preceding results relate to metal pipes placed on the outside and exposed to cooling, while, in general, similar ventilating-pipes may be, and ought to be, made of earthen ware, and placed in the thickness of the walls or in the interior of buildings, which, exposing them less to cooling, would increase the effect obtained. In the case of large kitchens with wide fire-places, when the ranges are kept very hot, and are used almost all the time, it would be more economical to place a coal-grate in the lower part of the chimney, at about the top of the fire-place, and this would also be the most simple and direct method for country-houses.

107. Use of the lost heat from kitchen-ranges for ventilating and for heating baths. Besides the advantage of securing a change of air and the removal of bad odors from the kitchen, the hot-water pipes mentioned in § 105 serve to supply baths, which may be established with success, as mentioned in § 81 in barracks, as well as in those establishments where provisions are cooked for the poor, to be distributed to them gratuitously or sold to them at a low price. The addition of hot-water baths to these useful establishments might thus be made at very little expense.

An arrangement of this kind is adopted with success in the new lying. in house established by the administration of public assistance, rue du Faubourg St. Jacques, to utilize the lost heat from the stoves used for making plasters.

108. The baths may be heated also by means of ordinary hot-air kitchen-ranges without recourse to the use of hot-water circulation, or, what is better, by combining the two means of utilizing the heat lost from the range during the time the meals are being prepared.

109. Privies.-The necessary arrangements to be made in order to prevent the infection which these attachments to buildings often produce vary with the mode of construction adopted and the nature of the building.

The regulations for the construction of privy wells are as follows: The down-pipes should dip at their lower end into the contents of the well, or better into a fixed or movable copper basin, into which it is well when it can be done to force water from time to time in order to wash it. It follows from these arrangements that the only gases which can

ascend in these pipes arise from their internal surface or at the bottom of the pipes, and will not be very abundant, (Fig. 30.)

To prevent the gases from spreading to the interior of the rooms, water-closets called English closets are usually employed within dwellings. In less particular houses and in public establishments, there is simply placed under the opening a basin called Roger Mothe's apparatus, which tips and empties itself by the weight of the contents alone, and then returns and closes the opening.

These convenient means are not always sufficient to prevent the introduction of bad smells on account of small cracks in the joints of the apparatus.

In all cases it is better to keep the seat 1 or 2 inches above the upper edge of the bowl, letting the front and the two sides reach to the seat and to connect this space with a ventilating-pipe extending above the roof.

If this pipe can be placed near a source of regular heat, such as the kitchen-flue, or if hot-water pipes can be carried into it, as in the case of mansions heated by hot water, it would be easy to obtain a sufficiently powerful draught in this pipe.

But if this method is not available, as often is the case in small dwellings, the same effect may be secured by placing in the pipe a small gasburner, burning at most 1 or 14 cubic feet an hour, and which, by the aid of a transom, will illuminate the closet at the same time that it purifies it. A common lamp might even be made use of, burning or 3 ounce of oil an hour, (about to of a pint.)

36

The ventilating-pipe should be about from 46 to 62 square inches in area, and the small burner, burning 1 cubic feet an hour, would, in most cases, secure the renewal of 1,000 cubic feet of air an hour, which would suffice not only to expel all the gases coming from the seat and its descending-pipe, but even to renew the air of the room several times an hour by drawing in that of the surrounding corridors and also prevent the infection of the interior of the house.

110. Example.-Office of the Northern Railroad Company, (Fig. 31.)—If, instead of English water-closets, only open seats are used, or even those called Turkish seats, similar arrangements would produce the same results.

Fig. 31 shows the plan adopted with success in the office of the Northern Railway Company, where there are in the five stories twentyseven water-closets. The down-pipes serve for all the pairs of seats in each story, and are only three in number. They are 9 inches in diame

ter, and terminate in the movable copper water-basins, which form siphon-traps and prevent the rising of the gas from the well.

FIG.31.

All the ventilating-pipes from the seats are 4 inches by 16 inches inside. They terminate in a large vertical collecting-pipe, about 10 square feet in sectional area, serving as a ventilating-chimney, in which are placed vertical hot-water pipes, which in winter produce a general draught. In summer, when the heating is interrupted, the draught is produced by gas-burners kept burning in each closet.

Ventilation by means of hot-water circulation can evidently be kept up in summer by means of a separate fire for this special

purpose, which would be more economical than the use of gas.

The result of experiments made in February, 1863, was that the amount of air removed for each seat under the action of the draught, produced simply by an excess of 70 to 130 of temperature in the chimney over that of the external air, was more than 2,200 cubic feet an hour. Although much greater than is generally necessary, this amount would not seem excessive in similar cases where, in addition to the seats, urinals, often imperfectly rinsed, are used.

111. Arrangement adopted at Lariboisière Hospital, (Fig. 32.)-In this establishment, the closets on each floor contain three seats, with bowls,

R, of enameled cast iron, which empty into another bowl, S, forming the top of a down-pipe, U, of which there is one for each seat, but which, by a simple arrangement, might have been more economically made common to the three floors. These down-pipes carry the contents to a large hemispherical basin, O, of cast iron, always filled with water, in which their ends dip so as to prevent the gas from the well at the bottom from rising through the pipes. The contents run off from the basin O through the space X in the well, which is closed air-tight, and which, according to the regulations, should be provided with a pipe for the escape of gas to the top of the building.

It follows from this arrangement that the only gases which can rise to the top of the down-pipes in the closets are those which are formed. in the pipes. To prevent them from entering into the closets, and at the same time to renew the air in the latter, M. L. Duvoir has connected each of the under-bowls S with a pipe, T, leading to a ventilating-chimney common to all the closets.

The draught exerted by this pipe V, increased by the use of hot-water pipes or by other means, not only removes the gas developed in the down-pipe, but it carries off from the closets, through the hole in the seat, an amount of air equal to 1,200 cubic feet or more an hour to each seat.

Arrangements similar to the preceding have been applied with success in privies with Turkish seats in building b of the Vincennes Hospital.

SINKS.

112. When sinks, intended to receive kitchen-slops, give out a bad smell in spite of the precautionary measures prescribed by the sewerregulations, or when these regulations are not or cannot be observed, this unpleasantness may be removed by means similar to those just mentioned.

DINING ROOMS.

113. In these rooms, where the steam from the dishes and the heat from numerous lights, added to that produced by the people present, cause a temperature often insupportable, it is easy to apply the rules previously given.

It will usually suffice if the air be renewed four or five times an hour, producing the draught near the floor, and making use, as will often be very easy, of the heat from the wall-brackets to give it the required force.

If the room is brilliantly lighted by many chandeliers placed over the tables, an escape should be provided for the hot gases arising from the combustion by openings in or near the ceiling.

The openings for the admission of fresh air should be placed below the former, but removed as far as possible from the people.

It will then be found, as in the case of night drawing-schools, that the general rules will have to be modified.

As examples, chosen among those which apparently offer the greatest difficulties, I select the dining-rooms of the Hôtel de Ville, Paris.

114. State dining-room.—This immense room has the following dimensious: length, 156 feet; breadth, 34 feet; height, 38 feet; cubical content, 200,000 cubic feet; floor-surface, 5,300 square feet. There are usually at dinner there 180 persons at one table 152 feet long by 13 feet wide, which gives a contour of 2 × (152 + 13) = 330 feet, and allows each guest but 1.8 feet of space.

At dinners, the number of waiters cannot be less than 60. There are therefore 240 persons in the room.

The cubical space to each person is then

The amount of floor-surface to each person is

Under these conditions, it is illuminated by26 chandeliers, each containing 100 candles.. Table-candelabra of 6 or 7 candles each.............

Total number of candles

2, 600 592

3, 192

At the dinner given by the city to the Emperor on the occasion of his marriage, there were 420 persons at table. The number of waiters was at least 100; the cubical space for each person was then

200000
520

= 384 cubic feet,

and the floor surface to each person

5300
520

= 10 square feet.

The room was lighted, on this occasion, by 26 chandeliers of 100

candles each...

Table-candelabra..

Total.

2, 600 592

3, 192

Admitting that each candie develops 476 units of heat, the same as a person, the total number of units of heat developed in an hour, on that occasion, would be

(520 + 3192) × 476 = 1,766,912 units.

Supposing that air, at a temperature of 590, had been admitted at a height of 20 or 26 feet, and that this air, after its temperature had been raised to 95°, had escaped through openings in the ceiling, every cubic foot of air introduced would have carried off

.0766 × 36 × .237 = .6536 unit.