heated it takes a long time for it to cool off, and 

 it is thus a protection to the man who is too lazy 

 to fill the lamps, for his eggs are not apt to cool 

 off enough to kill the germs in them. But if he is 

 too lazy to fill the lamps, he is apt to be too tired 

 to go turn them down or add some cold water dur- 

 ing the hot part of the day, and when he goes to 

 look at the machine he finds the temperature 5 or 

 10 too high. How about the advantage then ? 

 If this happens on an extra warm night, or while 

 he is away from home, what becomes of the hatch ? 

 Which do you think most disastrous, underheat or 

 overheat ? We say overheat. 



The advantages of the hot air incubator are, that 

 the heat or hot air can be turned away from and 

 out of the hot air reservoir easily, quickly and 

 automatically, without disturbing the condition of 

 the egg chamber. The entire contents of the reser- 

 voir can be ejected by change of current, and re- 

 placed with cool air in a few minutes ; and by action 

 of the automatic regulator the heat currents are 

 again turned into the reservoir and the temperature 

 raised therein to the desired degree. This is done 

 by the action of a thermostat in the egg chamber, 

 controlling to a certainty and quickly the temper- 

 ature within the heat reservoir. This is an utter 

 impossibility with the hot water tank, so that when 

 it becomes overheated, as is often the case, you 

 must either turn down the lamp and wait for the 

 water in the tank to cool, draw off some of the hot 

 water and ,pour in some cold, open a large venti- 

 lator from the egg chamber and let the heat and 

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