^54 ^w Thrashing Alachines: Bed 



at Ifcast capable of threshing sufliciently, though at an increased 

 expence. These are either to shorten the cvlinder in a pro- 

 portionable degree to the extent of the impelhng power, or to 

 lessen its diameter, which will allow every other part of the 

 fabric to be in like manner diminished. This last mode ha» 

 hitherto been resorted to in the construction of small machines, 

 though I am not sure but that the principle, upon which it i» 

 founded, is erroneous ; at any rate, it can only answer where 

 ■the unthrashed grain is thinly passed through the feeding roll- 

 ers, as the closeness of the beaters would choke the cylinder, 

 and impede the operations of the mpchine. The other plan 

 I think better of, vi'z.. to reduce the length of the cylinder ex- 

 actly to the force employed to work the machine, in which 

 v/ay as much velocity may be safely used as is practicable 

 ■with machines of the largest size, provided that the other 

 parts of the work are constructed in a sufficient manner. Ac- 

 cording to this plan, the cylinder ought to be of the usual di- 

 •meter, but not to exceed 15 inches in length for a one hors© 

 power, and proportionally more, as the draught is augmented. 

 "With such a cylinder you may feed as thick in as is common- 

 ly practised, and you make up in thickness of feeding for thifc 

 increased breadth occupied upon the board when the diam.e- 

 tcr is only reduced. Such a cylind^-.r would stand more fa- 

 tigue, and be in less danger of breaking, than a long slender 

 one. To be sure it would be an aukward business to see it 

 At woik; but be this as it m.ay, it appears to me that 

 such would be the cheapest in the first instance, and the du- 

 Tablest of all small machines ; though in point of profit, I 

 believe they are all in one predicament. 



I ought to have noticed a circumstance which renders thfc^ 

 ^ail superior to small machines, and that is, that where hand 

 labour is used for thrashing, an inconsiderable part of the sheaf 

 is tiirashcd, whereas, in passing through a machine, every inch 

 of the straw receives the same beating as is given to the ear, 

 where the grain has its residence. This, especially when strong 

 rank wheat coaies to be thrashed, is a matter of great impor- 

 tance. The thrashing of the w4iole straw certaiuly occasions 

 an extra quantity of produce, but this can only be profitably 

 gained by using powerful im.plements ; for v/here small one^ 

 are used, the increased produce is eaten up "hy the increased 

 labour. Upon a farm of small size, where only one or two 

 ploughs arc kept, the occupier often threshes a good deal of 

 the grain himself, at least he has it in his power to examine 

 «vcry truss of the straw ; none of wliich things can possibly 

 happen where the concern is extensive. Upon small farms, 

 5iieh as apt: of lt»€ siac ^wdef««ttd«<i upon bj youj ccrrcspon- 



