1904.] Artificial Hatching of Chickens. 137 



with corrugated iron. It is lighted by four windows facing the 

 east, so as to avoid the sun's rays passing into the room. The 

 walls stand upon a double row of bricks, and the floor is laid 

 with Staffordshire tiles. Inside, the building is divided into two 

 compartments ; first, the outer porch, 5 ft. by 16 ft, where stores 

 are kept and lamps cleaned ; and, second, the incubator room, 

 27 ft. by 16 ft., connected by double folding doors. As a dozen 

 machines have to be accommodated in this room, the consump- 



Incubator House, showing System of Ventilation. 



tion of oxygen — both by the oil lamps heating the machines 

 and the requirements of 1,200 eggs — must necessarily be 

 considerable. Hence great attention was given to ventilation. 

 Fresh air is drawn into the incubator room by eight four-inch 

 pipes, shown in the drawing, the cowls of which are 6 ft. 

 above the ground outside, and the air enters the room below 

 the level of the machines, so that as it ascends both lamps 

 and eggs in the incubators receive a plentiful supply of abso- 

 lutely fresh air. Were the circulation downwards upon the 

 machines, the air before reaching the eggs would necessarily be 



