Appleton's cyclopædia of drawing, designed as a textbook for the mechanic, architect, engineer, and surveyor (1866)
Worthen, William Ezra, 1819-1897, [from old catalog] ed, Appleton, firm, publishers, New York. (1866. D. Appleton & co.) [from old catalog] · New York, D. Appleton and company · leaf 39
if seven lines be(fig. 61) ruled, enclos-ing six equal spaces, and the length be divided into primaries, as AB, BC,tfcc, the first primary AB may be subdivided into twelfths by two diagonals/I (; ji f running from 6, the mid- die of AB, to 12 and 0.We have here a very con-venient scale of feet and… … DRAWING INSTRIIMENTS. 19 C on tlie several parallels to the various intersections of the diagonals, weobtain 1 foot and any number of inches from 1 to 12. Plotting scales and rulers are scales of equal parts, with the divisionsplaced on a fiducial edge, by which any length may be pricked off on to…
