IQ2 SCIENCE OF SUCCESSFUL THRESHING, 



to separators built previous to the year of 1899, which were 

 fitted with the right-hand grain augers, it is necessary to 

 replace the old auger by a left-hand one, or the attachment 

 will not work. The Number Four Bagger is ordinarily used 

 with a left-hand grain auger, but it may be used with light- 

 hand as well. To do this, it is necessary to remove the 

 chain, and unbolt and reverse either the head or the boot. 



Caution Regarding the Sprocket-Chain. The chain in 

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

 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. As 

 the chain wears, the hook of each link may be closed by ham- 

 mering 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, al- 

 ways remove two links at a time so that an odd number, 

 three or five, of plain links remains between the cups or 

 "flights," 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. 



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- 



