Fig. 3. Is a longitudinal section on the line XX 

 of Fig. 4, showing the thermostat and its connec- 

 tions. 



Fig. 4. Is a view in cross section on the line YY 

 of Fig. 5. 



Fig. 5. Is omitted, as the four figures shown 

 are sufficient to explain fully. 



FIG. 3. 



Similar letters refer to similar parts throughout 

 the several views. 



