“4 MNCL Sa F

Had the coulter been placed where the inclination of the mould-board begins, the earth muft have fallen upon the rifing fide of the board almoft entire, and refifted pro- portionally more according to its greater firmnefs.

This fituation alfo greatly promotes the fteady motion of the plough, by lengthen- ing confiderably the part that moves below the furface; for the longer-or fhorter this part is, the more or lefs fteady muft the mo- tion be. Now, by the fituation of the coul- ter, the plough gains the fame advantages in point of length as if it were one continu- ed wedge; and confequently muft be much lefs apt to be pufhed out of its direction, than it would be, if made fhorter, by having the coulter placed nearer, or joining to the mould-board.

This fituation promotes fteady motion from another caufe. The foil. towards the furrow is always a little lefs firm, than that at fome diftance frorn it, being loofened by the treading of the cattle and rubbing of the plough. On this account, there is a conftant tendency in the plough to leave the firmer ground,

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