And now you shall draw B in its square thus: First divide the square
horizontally by the line e. f.; then bisect the lines a. e. and b. f. by
the line g. h. Next, you must first set properly the broad vertical limb
of the letter, distant its own breadth from the side a. c. of the square
a. b. c. d. Then erect the line i. k. on the inner side of the limb
already drawn, and distant from it one-tenth of a side of the square,
and let it cut the line g. h. in the point l.
Next, draw strips narrower and horizontal (to be produced hereafter into
the convex limbs) from the vertical band to meet the vertical line
i. k.--namely, at top, below the line a. b.; next, above the line e. f.;
and at bottom, above the line c. d.
Now set a leg of the compass on the point l. and describe a semicircle
to the right of the transverse strips, so that the extremities of the
circumference, in the vertical line i. k., below the side a. b., and
above the line e. f. may coincide with those short transverse lines.
Then bisect the narrow transverse strip which is above the line e. f. in
the line i. k. by the point m.; and indicate the breadth of the letter,
to the right of the semicircle, by the point n. in the line g. h.; and
afterwards draw from the point m. above the line e. f. in the direction
of f. a short horizontal line as great as need be: then describe a
semicircle which shall include this line, and the point n., and, at the
top, the side a. b.; and through n. let pass a vertical line. These all
combine to form, below, the concave of the curved limb, and above, its
convex.
Next, produce the transverse strip above c. d., in the direction of d.,
as far as required, and mark this q. Then bisect the line m. q. by the
line o. p., cutting the line n. in the point r.; and next describe a
semicircle touching the horizontal line e. f., the point r., and the
position q. Then indicate the breadth of this limb of the letter by the
point s. to the right of the point r. in the line o. p. and describe a
semicircle, touching the line m., the point s., and the side of the
square c. d. There will then remain in the letter three right angles to
be eliminated: the interior and lower one may be shaped into a curve by
a circle whose semi-diameter is two-thirds of the breadth of the broad
limb of the letter, and the exterior ones you shall fine to a point by
circular lines whose semi-diameter is equal to the breadth of that limb.
Another method.
Or you may make your B in this fashion: Let the side a. c. of the square
be divided into nine equal parts, and cut off the four superior parts by
the horizontal line e. f. Then erect your vertical limb as described
above; and the superior curved limb you shall make between a. b. and
e. f.; the inferior between e. f. and c. d.
Now divide a. b. into nine equal parts, and cut off four parts towards
b. in the point g.; then divide c. d. into five equal parts, and the
last, towards d. mark off in the point h. and join g. and h. by the line
g. h. which should touch on their exterior edges the superior and
inferior limbs of the letter. Now these limbs must be drawn of a
particular form; and the compass, in drawing the circular lines, must be
moved up and down their diagonals: and these two diagonals you shall
determine in this wise.
Divide a. e. into four parts; the lowest, above e., call i. e.; the
lowest of the five remaining, above c., call c. k. Then join the points
i. and b. and k. and f. respectively, by the lines i. b. and k. f. Upon
these lines move and turn your compass, & in this way you shall describe
both curved limbs: and they must both be broader towards the top than
towards the bottom, as follows naturally with the stroke of a pen, and,
moreover, while approximately round, they are not to be circular;
therefore you will have to move your compass at need along the
diagonals, and withal to assist it also with the hand, as I have done in
the picture on the following page.
[Illustration: B]