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INCUBATION 



The essential parts of an incubator consist of a 

 heating apparatus that is controlled by a regulator, 

 and an egg chamber that can be held at the required 

 temperature. Incubators are also supplied with ther- 

 mometers and means of ventilation. 



In the various incubators heat is brought into contact 



with . the eggs either by diffusion or radiation. In 



- diffusion incubators, hot air is evenly distributed through- 



FIG. 1 



out the egg chamber. In radiation incubators, the heat is 

 radiated from pipes or radiators that are heated either 

 by hot air or by hot water. A large part of the incubators 

 in use are of the diffusion type, in which the air is 

 heated by an oil lamp. In these machines the heated 

 air passes directly into the egg chamber and throughout 

 the interior of the machine. The eggs in the tray 

 are thus surrounded with air at the required tempera- 

 ture. Incubators in which the heat is both radiated and 

 diffused are also used. The more evenly the egg 



