IO4 SCIENCE OF THRESHING. 



boiler. The locomotive boiler is so called from its 

 resemblance to the type used in locomotive practice. 



Its parts are, first, a rectangular fire-box, a, held in 

 position in the shell of the boiler by stay bolts, c. 



Second, the waist, a cylindrical portion, d, through 

 which pass the tubes or flues, e, connecting the fire- 

 box with the smoke box, /. 



Third, the steam dome, g t from which the steam 

 may be taken. 



ILLUSTRATION IN SECTION OF BOILER. 



The flat portions of the boiler above the fire door 

 and over the front ends of the flues are stayed by 

 long rods called stay rods. The crown sheet over 

 the fire-box is supported by stay bolts. 



In a return flue boiler, the fire box extends the 

 whole length of the boiler, which is usually tubular, 

 and the flues come back through the shell returning 

 the smoke to the fire door end. 



