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QUARTERING OF TROOPS.
and breadth of the room. Thus a room 39' x 22', giving a mean of 30 feet, willrequire an opening of chimney of 4' 4" horizontal by 3' 3" perpendicular, the latterdimension being constant for all sizes of rooms. The flue of the chimney in thebrickwork should in this case be 9"x 131)", giving an area of 121 inches; but thepot on the top, where the smoke issues into the open air, should be regulated by therule laid down by Tredgold, viz. “ Let 17 times the length of the grate in inches bedivided by the square root of the height of the chimney in feet, and the quotient isthe area of the aperture at the top of the chimney, in inches.” In this case thelength of the grate is 30 inches, and supposing the total height at 25 feet, then the
statement is 30 ? —=102 inches area, or a clay pot of Ilf inches diameter, or a slate
top of 10 inches square.
8. The size of the rooms, according to the premises here laid down, will be asfollows:
A room for 18 men is the maximum size which should be introduced into barrackbuildings, because it is the largest room which can be heated by one fire-place.
9. I will now proceed to consider the subject of Light . In order to obtain a dueproportion of window-light, the rule is to find the cubic contents of the room in feet,and to extract the square root, which will give the area in feet of the window orwindows required. Divide this into as many parts as the room will admit of windows.For example, suppose a room for 18 men of the dimensions already stated. Thecubic contents are 9000 feet, the square root of which is 95 feet, to be divided intofour windows of 24 feet area each. For the width of windows, Sir William Cham bers has observed that he generally added the depth and height of the rooms on theprincipal floors together, and took fth of the sum for the width of the window.Thus, to find the width of window for a room whose dimensions have been stated,
22 -i-10*6
the case will be--= 4 feet, the width required. The dimensions of the
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windows will therefore be 4' x 6'= 24 feet area each. The top of the window shouldnot be higher than 1 foot 6 inches from the ceiling line. The pier between thewindows should never be less than the width of the window, otherwise it has a weakand diminutive eifect.
10. There are serious objections to enlarging the apertures of the window’s beyondwhat the rule prescribes; for the cost of the building is increased, the air in therooms is cooled proportionally in winter, and the expenditure of fuel must be aug-mented, in order to maintain a given temperature. Independently of the inconveniencearising from a glare of light (especially where the rooms face the south or west),during summer the rooms are over-heated.
11. The principle of ventilation is to admit pure air and to give an outlet for thevitiated air; the pure air to be admitted at the door within four or five feet of thefloor level, and the vitiated air to escape by an opening or openings at the ceiling.The rule laid down by Tredgold for the area of the tubes for the exit of foul air is asfollows : “ Multiply the number of people the room is to contain by 4, and divide by43 times the square root of the height of the tubes, in feet, (measured from the floor-line to the exit into the external air,) and the quotient is the area of the tube ortubes, in feet.” Three-quarters of the area, as found by the above rule, is sufficient