Improved Machine for culling Chaff. 293 



lefs as occafion may require, fo as to give the knife as much 

 p refill re againfl the hox as may be requifite to cut the flraw. 

 The knives are prevented from coming too forward, and oc- 

 casioning unneceffary friction, by the wedges under the 

 ftaples a a ; which wedges, as the knives wear, rnuft he 

 drawn out fo as to admit the knives to come more forward. 

 With the before-mentioned provifions it will be found very 

 eafy at any time to put on new knives, as the fprings, &c. 

 will always adjuft them to their work. 



On one fide of the. wheel is fixed a round block of wood, D, 

 in which there are four holes and a moveable fcrew; to this 

 block is ferewed one end of the feeding-arm, E, running nearly 

 horizontally to the crofs bar F, at the end of the box G; to' 

 which crofs bar E is attached by the pin b, moveable to five 

 different holes in F, by means of which, and the four holes in 

 the block before defcribed, twenty changes in the length of 

 the chaff may be obtained. The flraw is brought forward 

 by the rollers in the box G, the form of which is (hewn at 

 Fig. 1 ; which rollers are turned from the outfide by the rig- 

 gers or ratchet-wheels, H, one on each fide the box, which 

 move more or lefs, according to the flroke given to the crofs 

 bar by the fecding-arm and wheel: by this mode of feeding, 

 the flraw is perfectly at reft, and does not prefs forward at the 

 time of the knife cutting; and, by means of the pin being 

 taken out of the crofs bar, the feeding is inftantlv thrown off, 

 although the wheel and knives may continue their motion. 

 Under the box is fufpended the prefling weight I, which mav 

 be made more or lefs powerful by fhifting the weight on the 

 bearer K, to which it hangs, and alfo may be thrown 011 ' 

 either fide, more or lefs, as occafion may require; which 

 will be found ul'eful, in order to force the flraw towards the 

 knife, and to counterbalance the ratchet-wheel of the upper 

 roller: near the fulcrum of this bearer is fixed a chain, fliewn 

 by the dotted line c; its upper end fufpended from a roller; 

 at each extremity of which is a fmall bar of iron joined to 

 U 3 the 



