TESTING AND REGULATING 



249 



Heater without chimney 



nicely balanced by means of a counterpoise weight. On the 



other end of this arm there is a damper, suspended over the top 



of the heater, which opens and 



closes, thereby permitting the 



heat to enter the machine or to 



escape around the damper. Some 



thermostats regulate the size of 



the flame as well as the position 



of the damper. 



The position of the counter- 

 poise weight is usually located at 

 the factory, and seldom needs 

 attention; but it should be so 

 placed in point of balance that 

 it will develop sufficient leverage 

 to raise the damper which is hung 

 at the other end, as soon as there 

 is the slightest pull on the con- 

 necting rod which leads to the 

 thermostat. In other words, the 

 damper or tin wafer over the 

 heater should be a trifle heavier 

 than the counterpoise weight, 

 consequently lie flat over the vent 

 in the heater when the machine is 

 cold. 



We are cautioned not to tam- 

 per with the heat-regulating ap- 

 pliance, which is good advice in 

 a way, except that intelligent 

 tampering, which amounts to ad- 

 justing, is sometimes necessary. 

 Occasionally the regulator arm is 



found bent out of line, if it is metal, or perhaps warped, if it is 

 wood, in which case the alignment will have to be corrected, or 

 the damper will not fall directly over the vent in the top of the 



{Courtesy Buckeye Incubator Company) 



Fig. 158. — Complete gas heater for 

 incubator or brooder. 



