Now, since architects, painters & others at times are wont to set an
inscription on lofty walls, it will make for the merit of the work that
they form the letters correctly. Accordingly I am minded here to treat
briefly of this. And first I will give rules for a Latin Alphabet, and
then for one of our common Text: since it is of these two sorts of
letters we customarily make use in such work; and first, for the Roman
letters: Draw for each a square of uniform size, in which the letter is
to be contained. But when you draw in it the heavier limb of the letter,
make this of the width of a tenth part of the square, and the lighter a
third as wide as the heavier: and follow this rule for all letters of
the Alphabet.
First, make an A after this fashion: Indicate the angles of the square
by the letters a. b. c. d. (and so do for all the rest of the letters):
then divide the square by two lines bisecting one another at right
angles--the vertical e. f. the horizontal g. h.: then, in the lower
line, take two points, i. and k., distant respectively one-tenth of the
space c. d. from the points c. and d.: then, from the point i. draw
upwards to the top of the square the lighter limb; & thence downwards
the heavier limb, so that the outer edges of both may touch,
respectively, the points i. and k.: then let a triangle be left between
the limbs, and a point e. be fixed at top in the middle of the letter,
and next join both limbs beneath the horizontal line, and let this limb
be a third as broad as the heavier limb.
Now let the arc of a circle, applied to the top of the outside edge of
the heavier limb, project beyond the square. Then cut off the top of the
letter with a serpentine or curving line, so that the concavity decline
towards the lighter limb, and prolong acutely either limb of the letter
at the bottom to either side, so as to meet the angles of the square at
c. and d.: this you shall make with the arc of a circle, whose
semi-diameter is one-seventh of the side of the square; but the two
lower curves, mutually opposite, permit to extend so that each is a
third of the heavier limb, and this you shall obtain by the arc of a
circle whose diameter is equal to the breadth of the heavier limb.
Moreover, this same letter A you may cut off at top with the side of the
square, and then produce to a fine point in either direction, as you did
the feet below, yet so that the longer production shall be to the
fore-side (namely, the left); but in this case it will be necessary to
draw in the limb k. a little closer.
Likewise the same A you may draw in yet another manner--that is, pointed
at top. In that case let the limbs slope towards one another yet more
closely; then lower the transverse a little and double its width. You
may also cut off the limb at top bluntly, or sharpen it on the
fore-side. You ought to make yourself familiar with these three forms,
or whichever of them pleases you best.
And note likewise that in exactly the same fashion in which this letter
is acutely prolonged at top & bottom, are the other letters to be so
prolonged which are drawn with oblique lines, as V, X, Y, although a few
changes may be necessary, as you shall hear below.