68 THE HOME POULTRY BOOK 
of heat. Some people tack a piece of cardboard 
marked “Day” to one side of the tray and an- 
other marked “ Night” to the other side and make 
it a point to have the former show when the eggs 
are put back in the morning and the latter when 
they are returned to the machine in the evening. 
When the eggs are turned, they may also be 
aired or cooled. This is an important matter, for 
it helps to develop strong chicks. While the eggs 
are out of the machine, the door should be kept 
closed. The extent to which the eggs should be 
cooled depends upon conditions. Of course, they 
can be left out only a short time in very cold 
weather. Perhaps a safe plan for the amateur is 
to place a thermometer on the eggs as soon as they 
have been turned and restore them to the machine 
when the mercury has dropped to 85 degrees. It 
is not necessary to become unduly alarmed if the 
eggs are permitted through inadvertence to become 
cold. The writer once forgot a tray of eggs until 
they had been out an hour. Wondering if it would 
be of any use to continue the hatch, he broke an 
egg and found a live chicken. ‘The eggs were re- 
turned to the machine and heated up quickly, with 
the result that an average hatch was secured. 
