_Fig._ 2. shews one Side, and the Thickness of the Tongue the other Side, being the same. _a b_ shews the polished Surface (being a true Plane), whereon the Seed runs down to the Spindle. _c d_ the Back-side, which lies turned uppermost in _Fig._ 1. _b e d_ shews one End of the hollow Cylinder of the Tongue, thro’ which its Axis passes. The Length of the Tongue must be such, as will reach lower than just to touch the Bottom of the great Hole as a Tangent: for, if it be not longer than that, it might happen, that when the Mortise is empty of Seed, and the Tongue set up close, a Wheel might, in Turning, or otherwise, go a little backwards, and cause a Notch of the Spindle to take hold of the End of the Tongue, and tear it out of the Mortise: Therefore let the Tongue reach a little below the Spindle, as the pricked Line _g h_, in _Fig._ 3. of _Plate_ 2. doth. As for the Posture in which the Tongue ought to stand in the Mortise, it is shewn by the Three pricked Lines in _Fig._ 3. _Plate_ 2. where the pricked Line _g h_ makes an Angle of Forty-five Degrees, being the nearest that it can stand to the Spindle; the pricked Line _i h_ makes a somewhat greater Angle, and it is a mean (or middle) Distance from the Spindle; and the pricked Line _k h_ is supposed to be its greatest Distance, where the Tongue makes its greatest Angle with the Top and Bottom of the Mortise. If the Tongue stood so obliquely as to make an Angle much less than Forty-Five, the Tongue would rise too much against the Bevel of the Mortise, and the Spring would have the greater Difficulty in returning it to its Place, when driven back by the Force of the Notches. And beside, when the Tongue stood wide from the Spindle, there might be so much Room betwixt it and the Sides of the Mortise, that some Seeds might fall thro’ there. The Steel Spring is D, properly placed upon the Back of the Tongue, in _Fig._ 1. _Plate_ 3.