THE GRAIN HANDLERS 247 



the cut-off to fully close when the trip-crank is at its ex- 

 treme throw. 



Caution Regarding the Sprocket-Chain. The chain in 

 the elevators of all the grain-handlers must be kept prop- 

 erly adjusted. Since they are driven from the bottom, 

 when the chain is too loose, it does not hug the sprocket 

 properly and wears unnecessarily. On the other hand 

 the chain should not be so tight as to be in tension, for 

 this causes unnecessary friction and the consequent wear 

 on the chain and shafts. A worn chain that is liable to 

 come apart can have its usefulness prolonged. The hook 

 of each link may be closed by hammering its point, while 

 its back rests on the horn of an anvil or similar projection. 

 In this way the chain may be kept free from danger of 

 unhooking until worn so that it fails from weakness. 

 When necessary to shorten the chain, always remove two 

 links at a time so that an odd number, three or five, of 

 plain links remain between the cups or "fiights," as they 

 are called. This is necessary because the lower sprocket 

 has teeth engaging only alternate links of the chain and 

 the links with flights attached must skip the teeth. This 

 does not apply to the tailings-elevator chain, as elsewhere 

 explained. 



' Calculating a Quantity of Grain. Where a weigher is 

 not used, the amount of grain in a wagon-box, portable bin 

 or in any rectangular receptacle, may be calculated as fol- 

 lows : Determine the length, width and height in inches, 



