21: 6

12 : 0

In addition to the accommodation thus enumerated, there are, in the basement, rooms for the residence of the Janitor, together with furnace rooms, from whence warm air is conducted to the whole building.

136

Class Room, No. 2,..

Class Room, No. 3,

Class Room, No. 4,.

1st. Master's Room,

2nd. Master's Room,

Museum,

Library,

Laboratory,

VENTILATION

EVERY apartment of a school-house should be provided with a cheap, simple, and efficient mode of ventilation, by which the air, which is constantly becoming vitiated by respiration, combustion, or other causes, may be constantly flowing out of the room, and its place filled by an adequate supply of fresh air drawn from a pure source, and admitted into the room at the right temperature, of the requisite degree of moisture, and without any perceptible current. These objects may be attained by attention to the following particulars:

1. The location of the school-house must be healthy, and all causessuch as defective drains, stagnant water, decaying animal or vegetable substances, and manufactures, whose operations evolve offensive and deleterious gases-calculated to vitiate the external atmosphere, from which the air of the school-room is supplied, must be removed or obviated. 2. The means provided for ventilation must be sufficient to secure the object, independent of doors and windows, and other lateral openings, which are intended primarily for the admission of light, passage to and from the apartment, and similar purposes. Any dependence on the opening of doors and windows, except in summer, will subject the occupants of the room near such points to currents of cold air when the pores of the skin are open, and when such extreme and rapid changes of temperature are particularly disagreeable and dangerous.

3. Any openings in the ceiling for the discharge of vitiated air into the attic, and hence to the exterior of the building, or by flues carried up in the wall, no matter how constructed or where placed, can not be depended on for purposes of ventilation, unless systematic arrangements are adopted to effect, in concert with such openings, the introduction and diffusion of a constant and abundant supply of pure air, in the right con- ` dition as to temperature and moisture.

4. All stoves, or other heating apparatus, standing in the apartment to be warmed, and heating only the atmosphere of that apartment, which is constantly becoming more and more vitiated by respiration and other causes, are radically defective, and should be altogether, without delay, and forever discarded.

5. Any apparatus for warming pure air, before it is introduced into the school-room, in which the heating surface becomes red-hot, or the air is warmed above the temperature of boiling water, is inconsistent with good ventilation.

6. To effect the combined objects of warming and ventilation, a large quantity of moderately heated air should be introduced in such a manner as to reach every portion of the room, and be passed off by appro

priate openings and flues, as fast as its oxygen is exhausted, and it becomes vitiated by carbonic acid gas, and other noxious qualities.

7. The size and number of the admission flues or openings will depend on the size of the school-room, and the number of persons occupying the same; but they should have a capacity to supply every person in the room with at least five cubic feet of air per minute. Warm air can be introduced at a high as well as a low point from the floor, provided there is an exhaustive power in the discharging flues sufficient to secure a powerful ascending current of vitiated air from openings near the floor..

8. Openings into flues for the discharge of vitiated air, should be made at such points in the room, and at such distances from the openings for the admission of pure warm air, that a portion of the warm air will traverse every part of the room, and impart as much warmth as possible, before it becomes vitiated and escapes from the apartment.

These openings can be made near the floor, at points most distant from the admission flues, provided there is a fire-draught, or other power operating in the discharging flues, sufficient to overcome the natural tendency of the warm air in the room to ascend to the ceiling; otherwise they should be inserted in or near the ceiling.

Openings at the floor are recommended, not because carbonic acid gas, being heavier than the other elements of atmospheric air, settles to the floor, (because, owing to the law of the diffusion of gases among each other, carbonic acid gas will be found equally diffused through the room,) but because, when it can be drawn off at the floor, it will carry along with it the cold air which is admitted by open doors, and at cracks and crevices, and also the offensive gases sometimes found in school-rooms.

9. All openings, both for the admission and discharge of air, should be fitted with valves and registers, to regulate the quantity of air to pass through them. The quantity of air to be admitted should be regulated before it passes over the heating surface; otherwise, being confined in the air chamber and tubes, the excessive heat will cause much injury to the pipes and the woodwork adjoining.

10. All flues for ventilation, not intended to act in concert with some motive power, such as a fan, a pump, the mechanism of a clock, a firedraught, a jet of steam, &c., but depending solely on the spontaneous upward movement of the column of warm air within them, should be made large, (of a capacity equal to at least 18 inches in diameter,) tight, (except the openings at the top and bottom of the room,) smooth, (if made of boards, the boards should be seasoned, matched, and planed; if made of bricks, the flue should be round, and finished smooth,) and carried up on the inside of the room, or in the inner wall, with as few angles and deviations from a direct ascent as possible, above the highest point of the roof.

11. All flues for the discharge of vitiated air, even when properly constructed and placed, and even when acting in concert with a current