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 40
ny 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 thepaper without using the compasses, whose points, by frequent use, destroythe fineness of the graduation. On the scale… … horn (fig. 62), whose circumference is divided into 180 equal parts or de-grees (180°). In the larger protractors each of these divisions is sub-divided. Application of the protractor.—^To lay ofi a given angle from a givenpoint on a straight line, let the straight line (2 h of the protractor…
