A SELF-SUPPORTING HOME 



degrees, the top or regulating nut on the con- 

 necting-rod, immediately above the regulator- 

 arm, is screwed down until the disk is raised 

 one-fourth of an inch above the chimney 

 such adjustment being considered by manu- 

 facturers and expert operators as most desir- 

 able for incubation. The machine once being 

 "set" for this degree of temperature, any 

 excess of heat causes the thermostat to ex- 

 pand, which makes it press on the lower nut 

 of the connecting-rod ; so instituting a tension 

 that influences the regulator-arm at the point 

 of balance, raising the disk over the lamp 

 chimney in sympathetic conjunction with the 

 thermostat. 



Reverse the condition to a dying lamp or 

 sudden cold wave, and of course the thermo- 

 stat contracts, and general release of pressure 

 allows the regulator-arm to resume a normal 

 balance, which permits the disk to lie closely 

 down on the chimney. It will be readily 

 conceded that on a correct adjustment of the 

 machine before starting the hatch depends 



