X you shall form thus: Draw two vertical lines e.f. and g.h. distant respectively one-tenth part of the line a.b. from the sides a.c. and b.d. Then draw the two limbs intersecting one another in the form of a cross—the broad one so that at top, & with its hither side it shall touch e., & at the bottom, and with its farther side h.; but the narrow limb so that at top, and with its farther side it may touch g., & at bottom, with its hither side f. Then add its projections, touching, at top and bottom, the four angles a.b.c.d., & choose a semi-diameter of the larger circle of the length of a fifth part of a.b.; & with that you shall round out the four greater angles; but for the lesser circle you shall take a diameter as long as two-thirds the width of the broader limb.

Or you may vary X thus: Let everything be left as before except the narrower limb, which at top you shall make more erect by one-half the breadth of the wider limb; and so the upper part of the letter shall be less and narrower than the lower, and shall have a different aspect, as is shown below.