He Provides also Flowers to set over the Head of a Page at the beginning of a Book: But they are now accounted old-fashion, and therefore much out of use. Yet Wooden-Borders, if well Drawn, and neatly Cut, may be Printed in a Creditable Book, As also, Wooden-Letters well Drawn and neatly Cut may be used at the beginning of a Dedication, Preface, Section, &c. Yet instead of Wooden Letters, Capitals Cast in Mettal generally now serves; because but few or good Cutters in Wood appear.
He also provides Brass-Rules of about Sixteen Inches long, that the Compositer may cut them into such Lengths as his Work requires.
In the choice of his Brass-Rules, he examines that they be exactly Letter high; for if they be much too high, they may cut through Paper, Tinpan and Blankets too; And if they be but a little too high, not only the Sholder, or Beard, on either side them will Print black; but they will bear the Plattin off the Letters that stand near them, so that those Letters will not Print at all: And if they be too low, then the Rules themselves will not Print.
It sometimes happens through the unskilfulness of the Joyner, (for they commonly, but unproperly, imploy Joyners to make them) that a Length shall be hollow in the middle both on the Face and Foot, and shall run driving higher and higher towards both ends: Hence it comes to pass, that when the Compositer cuts a piece of Rule to his intended Length, the Rule shall Print hard at one end, and the other shall not Print at all; So that he shall be forced to knock up the foot of the low end, as shall be shewn in its proper place.
But the careful Master-Printer having found that his Brass-Rules is Letter high all the whole Length, will also examine whether it be straight all the whole Length, which he does by applying both the Face and Foot to the surface of the Correcting-stone; And if the Face and Foot comply so closely with the Correcting-stone, that light cannot be seen between them, he concludes the Brass-Rule is straight.
Plate 1.
Then he examines the Face or Edge of the Rule, whether it have an Edge of an equal breadth all the whole Length, and that the Edge be neither too thick nor too fine for his porpose.
He should also take care that the Brass, before it be cut out, be well and skilfully Planish’t, nor would that charge be ill bestowd; for it would be saved out of the thickness of the Brass that is commonly used: For the Joyners being unskilful in Planishing, buy Neal’d thick Brass that the Rule may be strong enough, and so cut it into slips without Hammering, which makes the Rule easily bow any way and stand so, and will never come to so good and smooth an Edge as Planish’t Brass will. Besides, Brass well Planish’t will be stiffer and stronger at half the thickness than unplanish’t Brass will at the whole: As I shall further shew when I come to Exercise upon Mathematical Instrument-making.