Set the plough upon a plank perfectly level (proved by a level) draw a chalk line a, b, on the plank, and let the heel (d) and the point of the share (c) touch exactly on it. Then drop a plummet line thro [sic] the centre hole (e) of the [illegible] & it falls 1 1/2 inch off from it; y is, if you stand a cross the beam it falls so much to y. right hand of the chalk line. And the depth from the bottom of your [illegible] to the plank is 18 inches. The line (f, g) from the end of the beam to one inch behind the point of a new share is just 9 ft. These three measures are the most essential. If they answer, a plough can hardly go ill. All should be made alike to one invariable measure; but I cannot bring a common country bungling Smith taught by myself to make these ploughs to be correct & if he makes a variation in one point, then others are necessary. From the beam (L) to y. strait [sic] line (i) is in the widest part 4 1/2 inches--- Measures of the plough not marked. If they do not come correct change the shares till they do; for I am sure of one: & you will find the plough go alone--- There is a heel pure movable; as fast as it wears, make a new one & put on; it is at the bottom of the heel.--- One of the ploughs has three small notches marked in the brace wh. [illegible] the breast or mouth iron to the body of ye. plough: of that plough there are the measures. Depth of the beam end from ye. plank 18 1/2 inches. Fall of the plummet line through the centre hole 1 1/2 inch to the right of the chalk line. From y^l end of y^l beam ton one inch behind the share joint 3 feet. Furrow width at heel 9 3/4 inches--Breadth at top from corner of breast to y^l line of y^l furrow 18 inches: in the other plow it is about 20, wh. is not so well--there follows will not be correct. If you find difficulties in their work g let me know them, & I will endeavor to be more particular in the explanation. AY---