276 WARMING AND VENTILATION. * 



A shelf fastened to eacli side-wall at half the height of the longitud- 

 inal pipe e ee secures the separate admission of hot air below and cold 

 air above. It is sufficient that these shelves be 10 or 12 feet long, but 

 they should be made of earthen ware, in order that they may not be too 

 much heated by the action of the air from the heater, which might pre- 

 vent the entrance of the cold air. 



The two pipes for warm and fresh air are 12 inches by 20 inches. 

 Four openings, g,g,g,g, placed in the ceiling in the center line of the room, 

 admit the mixture of warm and fresh air with a velocity of about 20 

 inches a second, (§§ 51, 52,) and in order to allow for the obstruction of 

 the grating they are made 28 inches by 35 inches. Eegisters are placed 

 at the lower part of the chimney to regulate the amount carried off, and 

 they are also placed in the warm-air and fresh-air pipes so as to obtain 

 the proper mixture. 



Such are the simple and inexpensive arrangements which serve to 

 maintain in this asylum a degree of healthfulness superior to that of 

 other establishments of the kind. 



59. Results of ex])eriment. — The plan just described was carried out, 

 with a few modifications in details rendered necessary by local condi- 

 tions and by work i^reviously done. The asylum was opened January 

 27, 1868, and experiments made there in the first part of February, 

 which gave the following results : 



Results of experiments made in Saint Ambrose Infant-Asylum. — The 

 inside work of this asylum was not finished till the latter part of Janu- 

 ary, and the hall was opened on Monday the 27th to the first children 

 that were presented. After three or four days of heating to bring the 

 interior to the proper temperature, the experiments were begun on the 

 31st January. 



In the first visit to the hall, it was noticed that the foul air was car- 

 ried off very well by all the openings, although the velocity appeared 

 considerably greater at those nearest the chimney, as is natural. It 

 would be easy to render the amounts carried off through the openings 

 more uniform, if deemed necessary, by placing a register at each opening 

 and regulating it once for all. 



The admission of fresh air is provided for by means of openings in 

 the ceiling, and its velocity does not exceed 18 or 20 inches a second. It 

 can be rendered entirely uniform by partially closing the openings far- 

 thest from the heater, but this is not necessary. 



The amount of air admitted into the heater to be warmed may vary 

 greatly according to the intensity of the fire, but, with the very moder- 

 ate consumption of 57 pounds a day, it was found to be, on the 6th of Feb- 

 ruary, 62,000 cubic feet; and on the 7th of February, 59,000 cubic feet, 

 raised from the external temperature 42°, the usual mean temperature 

 of the winter, to 88°, at which it was admitted into the room. The 

 heater, on account of the large dimensions of its chambers, was more 

 than sufficient alone to supply the room in winter with fresh air heated 



