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 49
oints of theinstrument to be placed at the angular points of any shaped tri-angle whatever. This instrument is cliiefly useful in transfer-ring of points from one paj)er to another. Tlie two points ofthe compasses A being set upon such points of the di-awing as have beenalready copied, the third,… … Wholes and halves.—For copying and reducing drawing to half size,compasses called wholes and halves are used (fig. 71), in which the longerlegs being twice the length of the shorter, when the former are opened toany given line, the shorter ones will be i2\ tooi3ened to the half of that line. By…
