Chap.m. O F H O R S E-H O E S. 447 



mered, about the twelfth part of an inch thick, which is fufficient 

 to refifl the prefTure of the earth. Tliicker plates than thefe would 

 render the fhare too heavy, and it would be much more difficult to 

 give them their proper bent. 



The two mould-boards join to the handles at HL, and lap about 

 an inch one over the other; or elfe they are faftened together by 

 riyets. They forni, in that part, an angle E, H, F, of Ibmewhat 

 lefs than 90 degrees, which is fufficiently acute to ferve inftead of a 

 coulter: tho' a coulter may alfo be ufed upon occafion, by placing 

 it a little more forward. 



From the lower part Z/ of the' handles, the mould-board fliould 

 pafs underneath the fin L, G, of the fingle fliare, and follow the 

 diredtion of that fin, as at G; being let in beneath, about an inch 

 and an half, according to the pointed line L, G, and firmly riveted 

 by three 11 rong rivets. 



The hind part of the mould-boards is fixed and fupported by the 

 Ray F, to which they are ftrongly riveted. This flay muft have ex- 

 actly the fame bend as the mould-board. 



Behind the lower part of the handles is another fi:ay, M, N, 

 quite dole to them, and about two inches below the top of the 

 mould-boards, to which it is riveted at both ends. This llay helps 

 to keep them firm: but its chief ufe is to prevent their being raifed 

 up by the prelTure of the earth againfi: their extremities yl and B, 

 v/hich would throw their common angle H too forward, and mif- 

 place the Hiare. 



The proper Hope of the mould-board cannot be fo well defcribed 

 by words, as it may be conceived by the figure, which reprefents at 

 F the convex infide of the one, and at ^the concave outftde of the 

 other. The diflance to which the earth is turned over, when the ■ 

 cultivator opens it in order to make a large furrow, depends on the 

 degree of this bending, and the fpace between the two upper extre- 

 mities of the mould-boards, E, F. 



The extreme back part of the mould-boards is cut Hoping at C 

 and D, almoft in a fegment of a circle. This Ihape helps to opei-ate. 

 a greater divifion of the earth. 



• The plate of iron, before it is bent, Ihould be cut nearly in the 

 fhape oij/'g. I J. 



The fize of the niould-boards» as well as the proper bending of. 

 them, depends a little on the quality of the land intended to be cul- 

 tivated. I have found that, for light foils,, tkey need not be bent . 



I quite. 



