82 



PRACTICAL POULTRY PRODUCTION 



leases the heat from the heater. On the other hand, as the 

 temperature of the incubator decreases the thermostat 

 contracts, lowering the disk so as to close the heater, thereby 

 retaining the heat. 



The thermometer. There are two general styles of 

 incubator thermometers, each of which gives satisfactory 

 results. One is placed on the egg tray, usually in contact 

 with the eggs and is known as the contact thermometer, 

 while the other is hung above the eggs. In using the ther- 

 mometer follow the manufacturers' directions unless there 



is a very good reason for 

 making changes. When 

 the contact thermometer 

 is used, some operators 

 prefer to have the bulb 

 touch two eggs so that it 

 may record the tempera- 

 ture of at least one fertile 

 egg. The thermometer is 

 usually placed in the front 

 of the egg tray, so that it 

 can be easily read without 

 opening the door of the 

 machine. 



Operating the incubator. 

 The incubator should be set 

 up according to the manufacturers' direction; and see that 

 the machine is sitting perfectly level, thereby causing an 

 even distribution of heat in the egg chamber. All parts 

 of the incubator should be in their proper positions and the 

 regulator should work freely. If the door of the machine 

 sticks, do not plane it off until the machine has been heated 

 up and thoroughly dried out. The machine should be run 

 at about 102° F. for a few days before putting in the eggs. 



Figure 82. — It takes several hours for the 

 machine to come back to its correct 

 temperature after the eggs are first put 

 in. Therefore, the regulator should not 

 be changed during that time. 



