78 Report on Trials of Plows. 



tofore been made to my knowledge. Having remarked that the 

 point of the share is always disposed to wear round, I make the 

 point round at first. I also make it about twice as broad as usual, 

 and of course much thinner. The edge of the share is likewise 

 made rather concave or hollow, this being the shape to which it 

 naturally wears. In consequence of this they wear much more 

 uniformly, will last longer and be less expensive. 



"It is also a fact that the broad share or coulter point Avill 

 enter or strike into the ground much better than those of the 

 ordinary construction, and, being much thinner, will retain their 

 edge and work much longer without requiring repair. 



" In using the wrought iron share, the point or fore and lower 

 part of the mould-board, especially if the point of the share is 

 suffered to wear off very short, is liable to wear away. To obviate 

 this, I make a plate of wrought iron of suitable thickness, say 

 one-fourth of an inch. Fig. 7, and shape it to fit, or nearly fit, on 

 the front and lower part of the mould-board, and fasten it on with 

 the head of the main screw bolt, with which the share is fastened 

 on, taking care to fit the lower edge down snug to the top of the 

 share. This plate may be put on when needed, and renewed as 

 required. 



" If I apply a cast iron share, I make a birth or countersink on 

 tlie lower and front part of the mould-board (see q, Fig. 4, and i\ 

 Fig. 3), on Avhich I put my cast iron share, in the manner in which 

 Richard B. Chenowith, of Baltimore, fitted the share on his plow, 

 patented in the year 1808, but with the following alterations and 

 improvements: He employed two small screw bolts to fasten his 

 share on ; and to enable him to set the edge of the share deeper 

 as it wore off, he made the holes in his mould-board of consider- 

 able length, and in such form that the share could, when required, 

 be moved down or with the point and edge forward. Thus the 

 point and edge was extended, but the desired effect was not pro- 

 duced. The point and edge would naturally wear to a bevel on 

 the under side, and it was owinjx to this circumstance that it would 

 not penetrate into the ground; not because it wanted more length. 

 In my plow the share is fastened on with one screw bolt ; more 

 may be used, but are unnecessary. Having the point made round, 

 broad and much thinner than usual, with the edge rather hollow, 

 it is thus accommodated to the shape into which it has a tendency 

 to wear. When it is first put on, a small strip of wood or leather 

 is inserted between the edge of the mould-board and the share. 



