NATURAL AND ARTIFICIAL INCUBATION 



85 



for part of the eggs would then be hkely to cool much more 

 quickly than the others. 



Moisture and ventilation. Moisture and ventilation are 

 closely related and closely associated factors in incubation, 

 the amount of each depending upon the other. Moisture 

 is one of the uncertain factors in incubation on which there 

 are as yet no very satisfactory rules which will cover all 

 conditions. Odd as it may seem, good hatches are secured 

 both with and without using moisture under apparently 

 the same conditions. An experienced incubator operator 



Figure 83. — Cooling eggs from a mammoth incubator. 



usually works out, as the result of practice, the best amount 

 of moisture to use under his conditions. When too much 

 moisture is present, it may prevent the normal evaporation 

 that is necessary to allow sufficient space for the chick to 

 turn in the egg and break the shell. On the other hand, too 

 little moisture may cause the chick to become dry and stick 

 to the shell. Moisture is extensively used in hatching in 

 high altitudes and in places where the incubator is run in 

 a dry room. The following are the most common methods 

 for supplying moisture in incubators: Sprinkling the eggs 

 with warm water of about 100° F., placing a pan of water 

 or receptacle containing moist sand or a wet sponge inside of 



