POULTRY KEEPING 565 



testing. The final testing should be carefully made and with the 

 shortest possible exposure. 



The Air Cell. Books upon incubation devote much space to 

 this subject. If the air cell is too large the egg is too dry, while if not 

 large enough the egg is too moist, and the moisture supply can be 

 governed accordingly. Experience will teach the operator much 

 more about the air space than will written pages, and until he is ex- 

 perienced he need not attach very great importance to it unless it be 

 unusually large or small. By the end of the sixteenth day this 

 occupies about one-fifth of the space in the egg, and the chick ought 

 to occupy the remainder of this space. The air cell gradually in- 

 creases until the eighteenth day. Upon the eighteenth day, or the 

 nineteenth day at most, the eggs are turned and cooled for the last 

 time. After this do not disturb the eggs. If necessary, partly close 

 the ventilator slide. Leave the door closed. Of course, the thermo- 

 meter must be watched and the lamp filled and trimmed more care- 

 fully than ever. Do not be alarmed if the thermometer shows a tem- 

 perature of 104 at this time. No harm will be done if the eggs are 

 kept at that temperature a few hours. 



The operator is again cautioned to let the eggs alone during the 

 last two days of incubation. If the door must be opened to rear- 

 range the thermometer or to supply moisture, it should be for a brief 

 period only, and great care should be exercised not to jar nor change 

 the positions of the eggs. But the lamp should be kept in good order 

 and the regulator and thermometer watched closely. Some of this 

 has been stated before, but it will bear repeating, for many a good 

 hatching prospect has been blighted by over-anxiety or curiosity. 



At the end of the twenty-first day open the door and pull the 

 tray partly forward. Then remove the shells and, if any chick is 

 found with the shell dried upon it or in any way attached to it, 

 carefully liberate the chick and place it in the nursery below. Then 

 carefully close the door and let the machine alone for another six 

 hours unless the eggs are all hatched sooner. 



The eggs about all hatched, now is the time to clean and set up 

 the brooder, which should be heated a few hours before the chicks 

 are removed from the nursery. After the hatch is completed and 

 the chicks are removed from the nursery, the machine should be 

 taken apart, carefully cleaned, and set right for future use. The 

 brooder should be started at about 98 F. and gradually lowered at 

 the rate of 1 a week, according to the weather and the experience 

 and judgment of the poultry man. 



The chicks should not be fed until they are thoroughly dried 

 and have been out of the incubator at least twenty-four hours. The 

 first feed should be fine sharp grit or sand, upon which is sprinkled 

 a very little hard-boiled egg chopped fine. After this they should 

 be fed every three hours a little broken grain or, better yet, some of 

 the excellent prepared dry chick foods upon the market. Clean, fresh 

 water should be supplied from the start. Wet, sloppy food should bo 

 avoided. If none of the manufactured chick foods are at hand, a 

 substitute can be made by cracking a mixture of wheat, corn, and 



