428 O F P L O U G H S. Part IV. 



5. The finare A^, is pretty much like that of M. de Chateau- 

 vieux's plough, but fhnrter and narrower j fo that it cuts lefs wide 

 furrows, which M. Duhamel thinks the beft way of plowing. 



6. The coulter O of this plough paflcs through a mortife in the 

 beam, which is ftrengthened in this place by hoops of iron, to pre- . 

 vent the beam's being fplit by the driving in of the wedges PP which 

 fix the coulter. 



M. Duhamel thuiks this hind part of his plough preferable to that 

 of M. de Chateau-vieux's, for light lands : but it would not do fo well 

 in ftiff foils, becaufe the earth would be apt to clog about the fheat 

 at ^,; whereas it is thrown off by M. de Chateau-vieux's ploughv 

 M. Duhamel likewife approves of making the beam ftrait, as M. de 

 Chateau-vieux's is, inftead of giving it the bending from C to B ; 

 efpecially for ftiff lances. 



7. The beam C ^, is Rxed to the crofs flaves RR of the fore^ 

 carriage of this plough, by the fcrews and nuts SS. 



8. The fhafts 'TT, are faflened before by a crofs ftaff F, wKich 

 gives great folidity to the fore-carriage, and cannot be added to M. 

 de Chateau-vieux's plough: not only becaufe the wheel is too large, 

 but likewife becaufe it mufi: be fet forwarder or backwarder, in order 

 to make the Ihare cut more or lefs deep. 



The wheel of this plough is not fo large at that of M. de Chateau- 

 vieux's, becaufe the axle-tree, inftead of being inferted in the fliafts 

 TT, is let into the fide pieces X, which, are faftened to the fhaft by 

 the fcrews and nuts J^}\ 



The advantages of having the wheel fmaller, are, i. That the 

 plough is lefs apt to lean too much on its fide, and is more ealily 

 held upriglit; 2. That the crofs ftaff F may be added to the fore^ 

 carriage, by which it is rendered moreiblid; and 3. That the fore- 

 carriage may be made ftiorter than it could otherwife be. 



The bare infpedtion of tlie draught of this plough, ftiews that it 

 is made to cut more or lefs deep, by fcrewing the nuts 2^ more or lefs 

 tight, and putting a thicker or thinner wedge between the fide piece 

 A' and the fhaft; which is an eafier and quicker way, than chang- 

 ing the fituation of the wheel. But a readier method ftill, is, to 

 have under the ftiafts 'T'T, afalfe fhaft Z Z, fixed with hinges at & : 

 for then, by only flicking the peg a, into one of the holes d, the 

 beam is raifed or lower'd, in a moment, to whatever degree is 

 thought proper, without altering the pofition of the wheel. 



It 



