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 150
Fig. 205. of which the perpendiculars let fall from the fulcrum upon the direction ofthe forces are the radii. Thus, if the levers, Eig. 205, be acted on byforces of which the direction is shown by the arrows, the leverage, as it iscalled, or effective length of arm at which they act, are the…
