438 ADDENDA. NO. 2 



It is interesting to compare this result above stated, with the 

 quantity threshed by the flail, which may be done from Mr 

 Er kine's experiments. It appears from a trial made under his 

 directions, that two men threshed 3 bolls 3 firlots Scotch, or 

 22* Winchester bushels, in 8| hours ; but that if the fanners to 

 clean the corn had been properly driven, the quantity would not 

 have exceeded 3 bolls 2 firlots, or 21 Winchester bushels.* It 

 was also necessary to employ one woman to riddle the corn. It 

 likewise turned out, that the threshing-mill, from its velocity, 

 driving away more of the refuse, the sample it produced was bet- 

 ter and heavier, than from the flail. The result was, that seven 

 men, one woman, and four horses, could thresh and dress about 

 one-third more grain, in one hour, with a mill, than two men 

 and one woman could do in eight hours and a half, and not only 

 with more expedition, but more effectually. 



The size of one of the threshing-mills was as follows : 



1. Diameter of the horse-course, from centre to centre, 22 feet 

 10 inches. 



2. The horses make in a minute three turns of that course. 



3. Revolutions of the feeding rollers, 37^ times per minute. 



4. Ditto of the straw-shakers, 30 do. do. 



5. Ditto of the drum, 300 do. do. 



It appears that when six horses, instead of four, are employed, 

 they will thresh 192 bushels in four hours, which is at the rate 

 of 32 bushels per hour; whereas four horses thresh 150 bushels 

 in four hours, which is 37 bushels per hour ; consequently, a four- 

 horse power is the most economical size, at least for oats : but 



* It is a pity that the straw threshed by the flail, had not been passed 

 through the mill, to ascertain what additional quantity of grain would thus 

 have been obtained. A equal quantity of straw, threshed by the mill* 

 ught likewise to have been passed through it a second time, to have seen 

 what quantity of grain remained in it. 



