its

Of the Coulter. 2E

That ſome force is neceflary fax this purpoſe will eaſily appear. In the man- ner in which cattle are commonly yoked, the line of draught makes an angle of about 24 degrees with the ſole of the plough, or bottom of the tur- row,‘The tendency of the draught therefore, is always to pull the plougl out ofthe ground; and if the edge of the coulter were upright, it would give no oppoſition to this tendency, Nay, even if the coulter were pointed 24 de- grees forward, it would not have any efe, It muſt therefore projet fll more, in order that the reſiſtance upon. its upper edge may co-operate with the reſt of the plough, in oppoſing this ge- neral effed of the aſcent of the line of draught, This additional projection of