The Girt-Barrel marked d is Turned of a Piece of Maple or Alder-wood, of such a length, that it may play easily between the two Wooden Ribs; and of such a diameter, that in one revolution of it, such a length of Girt may wind about it as shall be equal to half the length contained between the fore-end Iron of the Tympan, and the inside of the Rail of the Inner-Tympan; because two Revolutions of this Barrel must move the Carriage this length of space.
This Barrel is fitted and fastned upon the Iron Axis, at such a distance from either end, that it may move round between the Wooden Ribs aforesaid.
¶. 17. Of the Press-Stone.
The Press-Stone should be Marble, though sometimes Master Printers make shift with Purbeck, either because they can buy them cheaper, or else because they can neither distinguish them by their appearance, or know their different worths.
Its thickness must be all the way throughout equal, and ought to be within one half quarter of an Inch the depth of the inside of the Coffin; because the matter it is Bedded in will raise it high enough. Its length and breadth must be about half an Inch less than the length and breadth of the inside of the Coffin: Because Justifiers of Wood, the length of every side, and almost the depth of the Stone, must be thrust between the insides of the Coffin and the outsides of the Stone, to Wedge it tight and steddy in its place, after the Press-man has Bedded it. Its upper-side, or Face must be exactly straight and smooth.
I have given you this description of the Press-Stone, because they are thus generally used in all Printing-Houses: But I have had so much trouble, charge and vexation with the often breaking of Stones, either through the carelesness or unskilfulness (or both) of Press-men, that necessity compell’d me to consider how I might leave them off; and now by long experience I have found, that a piece of Lignum-vitæ of the same size, and truly wrought, performs the office of a Stone in all respects as well as a Stone, and eases my mind, of the trouble, charge and vexation aforesaid, though the first cost of it be greater.
¶. 18. Of the Plattin marked d in Plate 9.
The Plattin is commonly made of Beechen-Planck, two Inches and an half thick, its length about fourteen Inches, and its breadth about nine Inches. Its sides are Tryed Square, and the Face or under-side of the Plattin Plained exactly straight and smooth. Near the four Corners on the upper-side, it hath four Iron Hooks as at a a a a, whose Shanks are Wormed in.
In the middle of the upper-side is let in and fastned an Iron Plate called the Plattin-Plate, as b b b b, a quarter of an Inch thick, six Inches long, and four Inches broad; in the middle of this Plate is made a square Iron Frame about half an Inch high, and half an Inch broad, as at c. Into this square Frame is fitted the Stud of the Plattin Pan, so as it may stand steddy, and yet to be taken out and put in as occasion may require.
The Stud marked d, is about an Inch thick, and then spreads wider and wider to the top (at e e e e) of it, till it becomes about two Inches and an half wide; and the sides of this spreading being but about half a quarter of an Inch thick makes the Pan. In the middle of the bottom of this Pan is a small Center hole Punch’d for the Toe of the Spindle to work in.