But the reason why four _Worms_ are generally made upon the _Spindle_, is because the Diameters of the _Spindle_ are generally of this propos’d size; and therefore a convenient strength of Mettal may be had on this size for four _Worms_; But should the Diameter of the _Spindle_ be smaller, as they sometimes are when the _Press_ is designed for small Work, only three _Worms_ will be a properer number than four; because when the Diameter is small, the thickness of the _Worms_ would also prove small, and by the stress of a _Pull_ would be more subject to break or tear the _Worms_ either of the _Spindle_ or _Nut_. And thus I hope I have performed the promise here I made at the latter end of _Numb._ 2. Whither I refer you for the breadth, and reason of the breadth of the _Worm_. ¶. 13. _Of the_ Bar _marked_ B _in_ Plate 8. This _Bar_ is Iron, containing in length about two Foot eight Inches and an half, from _a_ to _b_, and its greatest thickness, except the Sholder, an Inch and a quarter; The end _a_ hath a Male-Screw about an Inch Diameter and an Inch long, to which a _Nut_ with a Female-Screw in it as at C is fitted. The Iron _Nut_ in which this Female-Screw is made, must be very strong, _viz._ at least an Inch thick, and an Inch and three quarters in Diameter; in two opposite sides of it is made two Ears, which must also be very strong, because they must with heavy blows be knock’t upon to draw the Sholder of the square shank on the _Bar_, when the square Pin is in the _Eye_ of the _Spindle_ close and steddy up to the Cube on the _Spindle_. The square Pin of the _Bar_ marked _c_ is made to fit just into the _Eye_, through the middle of the Cube of the _Spindle_, on the hither end of this square Pin is made a Sholder or stop to this square Pin, as at _d_. This Sholder must be Filed exactly Flat on all its four insides, that they may be drawn close and tight up to any flat side of the Cube on the _Spindle_; It is two Inches square, that it may be drawn the firmer, and stop the steddyer against any of the flat sides of the said Cube, when it is hard drawn by the strength of the Female-Screw in the aforesaid _Nut_ at C. The thickness from _d_ to _e_ of this Sholder is about three quarters of an Inch, and is Bevil’d off towards the _Handle_ of the _Bar_ with a small Molding. The substance of this _Bar_, as aforesaid, is about an Inch and a quarter; but its Corners are all the way slatted down till within five Inches of the end: And from these five Inches to the end, it is taper’d away, that the _Wooden-Handle_ may be the stronger forced and fastned upon it. About four Inches off the Sholder, the _Bar_ is bowed beyond a right Angle, yet not with an Angle, but a Bow, which therefore lies ready to the _Press-man_’s Hand, that he may Catch at it to draw the _Wooden-Handle_ of the _Bar_ within his reach.