20 Of the Coulter» and being, in general, thrown up to its top, the coulter is cleared of them in that part chiefly employed in cutting the furrow- A

But if the edge of the coulter were perpendicular, it would carry along with it the roots which it does not cut, which would greatly increaſe the refiſ- tance which it meets with, and would frequently choke the plough, and ſtop its motion. In like manner, when the coulter comes to a ſtone, it makes it riſe upwards, in which direion it is more eaſily moved; whereas, if the edge were perpendicular, it behaved ta force it ſtraight forward.

Another advantage attending this in- clination of the coulter, is, that it tends to keep the plough in the ground,

That