This Crank, by its other End, passing thro’ the Two Legs of the Fork E, and equally distant from the Top and Bottom of it, turns the Spindle by the Motion of the Wheel which is fixed on the other End of the wooden Spindle. If this Crank were to turn the Spindle by a single Pin, instead of this Fork, the Seed could never be delivered out equally to the Ground; for as soon as the Pin began to descend, and decline from being perpendicular to the Horizon, it would, by its own Weight falling down, turn the Spindle half round in a Moment, and there remain with its other End downwards perpendicular to the Horizon under the Spindle, until the Crank reached it there, and so no Seed would be turned out by one Semicircle of the Wheel, and a double Proportion would be turned out to the Land that was measured by the other Semicircle; but the hinder Leg of the Fork, bearing against the hinder Part of the Crank, prevents this Inconvenience. The Line _f g_ is Part of the Surface of a Board, thro’ which the wooden Spindle passes, and by which it is held in its Place; as shall be shewn hereafter. The Axis of this wooden Spindle ought to fall into a Line with the Axis of this Brass Spindle; but, unless Care be taken to prevent it, the wooden Spindle will so much wear the Hole thro’ which it passes, and be worn by it, as to have Room in the Hole to deviate from this Exactness, and may descend so low, that the Crank may come out of the Ends of the Fork; and for this Reason it is, that the Fork is made so long as it is; but when this wooden Spindle does, by the Contrivances hereafter shewn, keep its Axis in a Line with the Axis of the Brass Spindle, or very nearly so, then the Legs of the Fork need be no longer than half an Inch; and in that Case, the Joint of the Crank, which is perpendicular to the Spindle, must be shorter, or else descend deeper into the Wood, so that its End, which turns the Fork, may be in the Middle betwixt its Bottom and the End of its Legs. The Use of the other End of the Spindle is this: When we have a mind that it should be turned by the left Wheel instead of the right, we screw in the Fork into the Hole I, and place a short Screw in the room of the Fork, to hold down the Slider. _Note_, It is not absolutely necessary, that the hollow Cylinder, which appears on the Sides of the Seed-box, should both, or either of them, project farther than the Flanches; but I think it better that it should do so, at least, on that Side which is next to the Fork. This Cylinder should be bored as true, and as even, as the Barrel of a Fusil is bored: and the Edges and Surfaces of its Ends must be smooth, and without Jaggs, to the end that the Wreaths may turn glibly against them. The Figure or Shape of all Sorts of Seeds disposes them, more or less, to form an Arch, when they are pressed from above, and confined on all Sides.