66 MRS. BASLEY'S WESTERN POULTRY BOOK 



change in the incubator at the time of hatching. The air is heavily 

 charged with moisture, and the temperature always rises during a 

 hatch from the activity of the chicks, and it is exceedingly difficult 

 to regulate the temperature when the incubator is full of chicks 

 in all stages of hatching. The rise of temperature does not hurt 

 the chicks that are just breaking out of the shell, but if it takes 

 place two days too soon, it will ruin the hatch of the heavier and 

 slower breeds. Experiments that I have made along these lines 

 have always given the same results. 



Turning the Eggs 



The eggs must be left for forty-eight hours after being placed in 

 the incubator before being turned. After that they should be 

 turned twice a day, or oftener. In this we should imitate the hen, 

 for she not only turns her eggs constantly, but always shifts their 

 position, pushing those that are on the outside into the center of 

 the nest. It is really more important that the eggs be moved or 

 shifted from their position or location in the tray, than merely 

 turned, as it shifts the locations of the eggs in regard to weak 

 germs or infertile eggs. 



If the eggs are not turned during the early stages of incubation, 

 many of the germs will dry fast to the shell and die, and the egg 

 will be lost. When the egg is not turned during the latter part of 

 incubation, the embryo does not develop properly, has little chance 

 of hatching or may prove a cripple. 



The turning and moving of the eggs gives exercise to the em- 

 bryo ; it is a species of gymnastics for strengthening the chick. 

 The first forty-eight hours and the last forty-eight hours the eggs 

 must not be turned. 



Cooling the Eggs 



Cooling the eggs I consider an important matter in our Ameri- 

 can incubators. The first week, following the hen's example, the 

 eggs require but little cooling beyond the time it takes to turn 

 them. The second week, as soon as the eggs are turned, replace 

 them in the machine and leave the door open for five minutes ; after 

 this increase the time, a minute or two each day, till at the end the 

 eggs are being aired or cooled fifteen or twenty minutes. 



Cooling the eggs helps to make the shell brittle, so that the chick 

 at the proper time can break its way out. Cooling the eggs con- 

 tracts the shell and heating it up again expands it and this con- 

 traction and expansion gives the shell its proper brittleness. As 

 the eggs warm up again, an almost imperceptible moisture comes 

 over them, which takes the place of the perspiration of the hen, and 

 obviates the necessity of sprinkling or dampening the eggs. So in 

 our incubators it is necessary to cool the eggs. If this has been 

 done properly the chicks will be strong and vigorous and few will 

 die in the shell. 



Testing the Eggs 



All sterile eggs and dead germs should be tested out. Egg 

 testers are sold with all incubators and very little practice will en- 

 able even a beginner to detect the sterile eggs and dead germs. 



