moisture escape together, open the door and risk 

 chilling the eggs, take out the eggs and sprinkle 

 them with tepid water, or let the eggs cook. In 

 a properly constructed hot air incubator (not one 

 with single wall or thin walls) the heat is easily 

 confined and controlled, being automatically sup- 

 plied or cut off by the regulator, which acts as 

 does the safety valve of a steam boiler. It also 

 consumes less oil than the hot water machine. 



The disadvantages of the hot air incubator are 

 that the kzy man who cannot look at it once in 

 24 hours may let the lamps burn out and the 

 machine cool down. Then, if somebody should 

 deliberately put the lamps out, it would cool off, in 

 the course of time. 



But how about if somebody deliberately (or 

 otherwise) turned up the lamp of the hot water 

 incubator, would it not go to the other extreme ? 



The sage who says water in the heater tank is 

 like the hot blood in the hen, knocks the " moist 

 heat" theory in the head, for a setting hen does 

 not sweat. Neither does a very warm dog. The 

 overheated dog pants, and drops of moisture fall 

 from his tongue ; an overheated hen also pants. 



But there is a time (we almost forgot to mention 

 it) when the water tank gives moisture to the eggs, 

 and that is when it springs a leak, which, in the 

 majority of hot water machines, and especially 

 cheap ones made by contract, is as likely to occur 

 in the middle of a hatch as at the beginning or 

 end or may happen as easily at midnight as at 

 daybreak. If you are on the spot just at the time 

 26 



