64 PROGRESSIVE POULTRY CULTURE 



to increase the humidity of the air surrounding the 

 eggs. 



Allow the hens to come off of the nests daily. If 

 there are many hens sitting in the room it may be neces- 

 sary to keep the fronts of the nests closed and regularly 

 every morning open the slatted doors for half an hour. 

 If any hens fail to come off for their daily feed they may 

 be gently removed from the nests by hand. If there are 

 too many hens to be all let out together, they may be 

 set free by squads. (A half hour is long enough to allow 

 the hens to be off the nests at one time. At the end of 

 that time look to the nests and see that every one has a 

 hen sitting upon the eggs. 



Eggs under hens usually hatch out on the twentieth 

 day. The hens should be left in peace while the chicks 

 are coming out of the shells and for twenty-four hours 

 thereafter. 



ARTIFICIAL HATCHING. 



If the poultryman desires to keep his hens laying 

 eggs or wishes to do hatching out of season or aims to 

 produce chickens in great numbers he usually resorts 

 to hatching by machines. 



Artificial incubation has been practiced for thous- 

 ands of years as is evidenced by the ancient hatching 

 ovens of Egypt and China. Mammoth central incubating 

 plants, constructed and managed as of old, are still to 

 be found in these countries. Eggs for hatching are 

 brought in from all the country around, are carefully in- 

 cubated in charge of expert and experienced operators, 

 and the chicks are distributed over the district to be 

 brooded and reared. 



The plan of establishing large central hatcheries and 

 distributing newly hatched chicks about the country is 

 already in operation in America but modern incubators, 

 with the exception of a few mammoth machines, are 

 limited in capacity to a few hundred eggs. These incu- 

 bators are owned and operated by poultrymen of more 

 or less experience, and the results show extreme varia- 

 tion. 



