et

ON yr oe PL OVC.»* xm

wedge, in this view, would. be exprefled by cutting away the right hand angle of the edge on which it moves.

Any perfon in.the leaft acquainted‘with the inftrument under confideration, will eafily perceive, that the defcription. now given of the right fide of it, refers to the plough with the plain mould-board..‘The curved mould-board* is a little different in form, aéts in a different manner, and is in- tended for a different kind of foil. It does not, however, oblige us to relinquifh the comparifon with the wedge, which will be found here equally convenient and fer- viceable as before.

The curved mould-board is in general more perpendicular to the horizon than the plain one. But the fore-part, inftead of being plain, is bent into a curved figure, re~ fembling a little the bow of a fhip, fo that here the upper and lower parts of the plough are nearly of the fame breadth. Towards the other end, this board projects a good deal more above than below; and here the plough is wider above than below. It is

eafy

* See figure 6.