78 Ventilation with Heating. 



doubling the height of the column of heated air, and so more 

 than doubling the power of its flow. The shutter was ordered to 

 be taken off the exit flue. The result was all that was expected, 

 the room was warm at the level of the inmates in one hour, 

 instead of two as formerly, from the lighting of the stove. 



Before these alterations were made, on going into the school 

 room just before closing time, ninety children and two or three 

 teachers having been in it for about four hours, with closed 

 doors and windows, the room was comfortably warm, though 

 it was cold enough to walk with a heavy overcoat outside, there 

 was a decided odour of humanity, still it was not at all oppressive, 

 although disappointing to the designer. After taking measure- 

 ments of the rate of flow of the air into the room through the 

 stove, and its rate up the exit flue, only then opened, the idea 

 suggested itself to try with the hand if there was a perceptible 

 increase of temperature at an elevation from the floor. To 

 ascertain this the teacher's platform was mounted, then his 

 chair, and lastly his desk. The result was as expected, but a 

 result quite unexpected was the disappearance of the smell 

 previously mentioned. Apparently the strata of pure warm air 

 kept steadily descending with little to break their continuity 

 excepting the rush of hot air through them from the stove as it 

 ascended at the lineal rate of some 300 feet a minute. There 

 has been no opportunity for making observations since the new 

 arrangement has been in use. There is probably more than 

 double the amount of air carried in. The top of the hot air 

 flue being well above the heads of the inmates, there will be 

 little or no tendency for the up rush of hot air from the stove 

 to carry any of the respiratory products with it, making it more 

 likely that the warm air will come down to the level of the 

 heads of the occupants pure, and in unbroken strata, and when 

 it gets into their lungs it should keep their heads clear enough 

 to make a rational speaker easily understood. By the above 

 process of reasoning and experiment we have apparently got the 

 pure air down to the noses of the audience, nature comes in to 

 assist us in getting rid of the respiratory products without the 



