Chap. I. F P L O U G H S. 425 



The coulter GH,Jig. i. fliould be made of good iron well fleeled. 

 A notch is cut in the beam to receive it. Jig. 9 and 10 ; and as the' 

 corners of that notch, C and B, againfl which the coulter bears 

 hardeft when the plough works, would foon be v/orn away if the 

 wood was left bare, it is proper to fecure them with two fmall pieces 

 of iron AB, CD, about the fixth part of an inch in thicknefs, 

 Icrewed on with flat headed fcrews. Thefe pieces of iron will keep 

 the coulter fteady in its place. 



The coulter fliould be pierced with feveral holes, from E to Fy 



Jig. 10, to take it up higher, or let it lower down, as occafion may 



require. It is faftened to the beam,which is pierced at E,fg. 9, by a 



Itrong iron pin with a fquare flat head, which is let into the beam. 



and lies even with it, as in^^. 10. The other end of this pin, £, 



Jig. 10, is a fcrew, fitted with its nut, by v/hich the coulter is 



faftened tight to the beam. Upon this fcrew hangs the handle ^, 



Jg. I, which ferves to turn it, and at the end of which is the key 



that faftens on the nuts of the iron pins which fecure the (liare. 



By this means, the key to turn the fcrews is always carried with the 



plough. 



M. de Chateau-vleux's coulters weigh but five or fix pounds 

 a-piece at moft, and frequently not more than three pounds. 



He places his coulter fo that its point G,Jig. j. jets out about an 

 inch beyond the outfide of the fhare L C. 



Fig. 1 2 reprefents the plan of the Ihare, with its dimenfions, as do 

 alfo^^. 13 and 14. The point fliould be made of good fteel, and 

 the reft of good iron, neither too foft, nor too highly temper'd, that 

 it m.ay not be fubjeft to break or bend. The tail of the fhare, AB, 

 Jig. 12, fliould be thickeft from y^ to C, becaufe that is the part 

 which bears the greateft ftrefs. Its thicknefs diminidies gradually to 

 B, where the ihare is faftened to the ground-reft. This tail i.s 

 pierced with two round holes at ^ and B,Jg. 13, through which arc 

 put the iron pins D E, FG, Jig. 12. which have fipare flat heads, 

 lying even with the tail of the fliare. Thefe pins pafs through the 

 ground-reft, where they are faftened on the other fide by the nuts 

 EG. A third round hole may be added at x jig. 13, in order to 

 faften the Ihare ftill more firmly to the ground-reft, with a fliort 

 "flat headed fcrew. 



M. de Chateau-vieux has likewife made feme ploughs with the 



round holes a /',Jg- i 3, near y^and B, that the iron pins D E, FGp 



Jig. 12, might not traverfe the tenons of the ftieat and handles j and 



I i i inftead 



