206 Farm Poultry 



their eggs with their wet feathers, has led some to 

 sprinkle the eggs at various periods during the 

 process of incubation. This, however, has been 

 shown to be unnecessary, except possibly in local- 

 ities where the air is very dry. Poultrymen have 

 also learned by close observation that, in the nest, 

 particularly as the period of incubation advances, 

 the eggs are arranged mostly with the large end 

 uppermost or toward the outer side of the nest. This 

 is probably due to the form of the nest and the 

 fact that the small end of the egg is heavier in 

 proportion to its size than the large end; that is, 

 the center of gravity approaches the small end, 

 which is, as incubation progresses, due to the devel- 

 opment of the air-chamber in the large end. The 

 fact that the eggs are arranged with the large end 

 uppermost, has led some persons to place the eggs 

 in the incubator trays in a similar position. With- 

 out doubt, the position of the eggs does not have 

 any particular influence on the hatching. 



Many tests have been made to determine the 

 actual temperature of eggs when natural incubation 

 is taking place. These tests show a considerable 

 variation until the ninth or tenth day. Until this 

 time the eggs seldom reach 100.* Although the tem- 

 perature of the fowl is usually above 106, yet the 

 temperature of the eggs is seldom raised above 103, 

 owing to the fact that heat is applied only on one side. 



* "Incubation and Its Natural Laws," Cyphers. 



