WARMING AND VENTILATION. 2iO 



the cbimney-flne, could have been heated by a special fire. This useful 

 appendage was given up for the same reason as the other. 



The foal air is carried off through ten flues, a, a, a, (Fig. 14,) made in 

 the thickness of the walls. The required velocity of the current beiug 

 2.3 feet a second, (§ 50,) the clear sectional area of each flue has been 



fixed at — — T— - = .78 square feet. 

 10 X 2.3 



The size of the openings might then be 1 foot by 9 inches ; but, their 

 area being reduced by a register which cuts off about one-third, they 

 have been made 1 foot square. 



These flues open into collecting-flues arranged under the floor on each 

 long side of the building; each of these collectors being able to carry off 

 at a maximum 9 cubic feet a second, with a mean velocity of 3 feet a 

 second, (§ 50.) They have at their mouths a sectional area of 2.7 square 

 feet, beiug about 19 inches square ; but, at the first part, up to where 

 the third down-flue enters, their areas have been reduced each to l.G 

 square feet, they being 1 foot by 20 inches. 



The transverse collectors, c, c, in which the air should have a velocity 

 of 4 feet a second, (§ 50,) have each a sectional area of only 2 square 

 feet in their transverse portion, being 1 foot four inches by 1 foot 

 7 inches, and they are but 2 feet 7 inches by 1 foot 7 inches where 

 thej' enter the chimney, while there they should carry off 18 cubic feet a 

 second. 



The chimney, which should carry off 18 cubic feet a second at the 



18 

 velocity of 7 feet a second, (§ 50,) should have the area f— -^'^^ square 



feet, or be 1 foot 7 inches by 1 foot 7 inches. It really has a sec- 

 tional area of 5 square feet, which is larger than necessary. It contains 

 the smoke-flue, and it has, near the bottom, a little grate 10 inches by 

 10 inches, forming a heater, in which a little coal-fire may be made in 

 mild weather in order to keep up the circulation of air. 



The introduction of fresh air is made in accordance with the rules 

 given in §§ 51, 52. 



The fresh-air supply for the heater A is obtained by means of a pipe, 

 B, carried from the garden and passing under the floor. At its outer 

 end, this pipe is connected with a sort of chimney connected with a grat- 

 ing to prevent the introduction of foreign bodies. 



The air to maintain the draught of the fire is taken from the little 

 room C. 



The warm air supplied by the heater passes to the upper room by 

 pipes, d d d, eee, placed under the floor of the attic-room in the line of the 

 building. The construction of the roof did not permit of using only a 

 single pipe, which would have been suflicient. The cold air to be mixed 

 with the warm air is taken in the upper room, where it is deflected 

 toward the pipes by means of slats, so as to be delivered above the warm- 

 air pipe d d d. 



