A text-book of geometrical drawing, for the use of mechanics and schools, in which the definitions and rules of geometry are familiarly explained .. (1850)
Minifie, William, 1805-1880. [from old catalog] · Baltimore, W. Minifie & co. · leaf 113
. Fig. 2. 1st. The SPAN of an arch is the distance between the points ofsupport; which is generally the width of the opening to be cov-ered; as A, B. These points are called the springing points; themass against which the arch rests is called the abutment. 3rd. The rise^ height or versed sine of an… … --^M:^^
