ftOl MBLC f 



Q. \\ ic degree of heat ncccssarv to futic ; 



legrcct. 

 Steel? 



s ni" !*.ilcrs are generally used 

 threshing engine? 



ic boiler and the tubular boiler. 



Q. About what amount of heating and grate surface 

 jiiircd per horse po\ iluc boiler? 



A!H.::! i 5 square feet of heating surface and # 

 re feet of grate surface. 



Q. \\ evaporation 



ue boiK: 



mnds of water to i pound of coal. 

 Q. How do these dimensions compare in a tubular 



A tubular boiler will require X less grate 

 v.-ill evaporate about 8 pounds of water to I pound of 



Q. V. you consider the most available? 



The tubular boiler? 

 Q. Why? 



It is the more economical and is less liable to 

 "collap? 



What do you mean by "collar 

 It is a crushing in of a flue by external pressure, 

 a tube of a large diameter more liable to col- 



