250 COMMERCIAL POULTRY RAISING 



heater. Then again, the tin wafer which acts as the damper may 

 be bent or twisted in some trifling manner, or thrown out of poise, 

 which will not allow it to settle evenly over the vent. Note these 

 things carefully, and your common sense will tell you if they seem 

 to function correctly. 



Adjusting Regulator. — As soon as the thermometer registers 

 I02 degrees, the connecting rod between the regulator arm and 

 the thermostat should be adjusted by means of a thumb-screw 

 so that sufficient tension is placed on the regulator to raise the 

 damper about an eighth of an inch, perhaps a sixteenth of an 

 inch, over the vent in the heater. Then, if the heat increases 

 and the thermostat expands, this expansion will transfer greater 

 tension to the connecting rod, which in turn lifts the damper and 

 permits the excess heat to escape. 



The temperature of 102 degrees should be maintained for 

 several hours, preferably twenty-four hours, before the eggs are 

 placed in the machine, and this temperature should be attained 

 without having to turn the flame up so high as to be in danger of 

 smoking. Once the machine has been adjusted to "blow off," 

 so to speak, at 102 degrees, and it has been found to work satis- 

 factorily, do not meddle with it. 



When the eggs are first placed in the chamber, though the 

 temperature was correct previously, the heat will fall instantly. 

 In fact, the thermometer will probably fall so low as not to read 

 at all; but do not be alarmed, this is to be expected, and is due 

 to the temperature of the eggs. It is likely that the eggs had a 

 temperature of 50 degrees, and if there are several hundred of 

 them in the one chamber, it will take twelve hours or more for 

 the incubator to warm them to the correct temperature. 



Remember that you have this latitude to depend upon in the 

 operation of a machine: Several hours are required to affect the 

 interior of the egg a single degree. That is, if you should sud- 

 denly find something wrong with the heating apparatus and the 

 thermometer registering 98 degrees or 106 degrees, it does not 

 necessarily follow that the interior of the eggs is that temperature. 

 And the more advanced the hatch, the greater the increase in this 



