Chap. ir. -OF DRILL-PLOUG HS, ^41 



pins run through the ftandards into them : and to take off the friclion 

 of the axle tree againft thefe pieces of wood, it may be made to tarn 

 on two friiflion wheels, placed in the lower part of them ; or rather 

 on four or fix fmall iron rollers turning on their axes* in a box in- 

 ferted in each of thefe pieces, which may be raifed, or lower'd, by 

 means of a row of holes in the llandards, through which the iron 

 pins are put, fo as to give the axle tree room to rife to the height that 

 ihall be thought neceffary to make the fliares pierce to the intended 

 depth, before the weight of the drill Ihall reft upon the axle tree. 



That the axle tree moving on fuch rollers, will have lefs friftion, 

 or require lels ftrength to make the wheels turn round, c\en v\heir 

 the weight of the vv^hole inftrument lies upon it, than it has in the" 

 blocks, with only the weight of the grain, is evident from the follow- 

 ing fadt. The gentleman who firft thought of this invention, applied 

 it to a roller of four tuns weight, v/hich is now drawn with eafe by 

 two ordinary horfes, even acrofs his nlowed grounds. 



It appears from this eafy motion of the roller, that there can be no 

 danger of the axle tree's turning, though loaded with the weight of 

 the whole inftrument. Other confiderable advantages will alfo arife 

 from the drill refting thus on the wheels : for the labour of the 

 plowman will be greatly leffened, the inftrument will move fteadier 

 and more uniformly, and the draught will be much eafier for the 

 horfes. 



M. Duhamel does not feem to have provided fufficiently for cover- 

 ing the feed. We think that may eafdy be done, by fixing to the 

 lower fide of the table, a little behind each fliare, two thin plates of 

 iron, or two pieces of board, in an angular form, but notquitejoined to- 

 gether, thus \/ . They fhould reach, as nearly as pofiible, fo low down 

 as to be level with the furface of the ground when the fhares have 

 pierced to the depth intended. Their fore part iTiould extend beyond 

 the width of earth that is turned up by the fhare, which they will 

 colledl into the furrow; and being open behind, if they happen at 

 any time to colledt more earth than was turned oft" by the fhares, it 

 will efcape through that opening, without clogging the drill. 



* Thefe rollers are made in great perfeilion, by Mr. Stevens, iion-msnger, in the 

 Hay-Hiarket, London. 



Lll CHAP. 



