FIRING WITH VARIOUS FUELS 4! 



about the same as that of straw, consequently it takes about 

 two and one-half tons to equal a ton of coal. 



Smoke Box. Any openings or holes in the smoke-box 

 let in outside air and have a tendency to destroy the draft. 

 The smoke-box door should fit tight and if broken, should 

 be replaced with a new one or repaired in a substantial and 

 workmanlike manner. 



Removing the Ashes. For each one hundred pounds of 

 coal or an equivalent amount of other fuel, about 150x3 

 cubic feet of air is required to support combustion, that is, 

 to allow the fire to burn. Nearly all of this large amount of 

 air must pass through the draft doors into the ash-pan and 

 thence through the grates. With this in mind, it is easy 

 to appreciate the necessity of keeping the ashes out of the 

 ash-pan so that they do not obstruct the passage of air. 

 Furthermore, if allowed to accumulate so that they touch 

 the grates, even at one point, the grates will be deprived of 

 the cooling effect of the air and consequently be warped or 

 melted so as to render them worthless in a very short time. 



Before removing hot ashes, see that there is no straw, 

 dried grass or other highly inflammable substances on the 

 ground where they will be likely to catch and spread fire 

 dangerously. If these materials are present, be prepared 

 to quench the fire, should they ignite, before it gets beyond 

 control. 



Rocking-Grates. In order to shake the ashes from the 

 grates when firing with coal, without disturbing the hot 

 coals, rocking-grates are sometimes used. The "Case" 



