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 73
It will be remarked that, in all cases of circles tangential to each other,their centres and their j)oints of contact must lie in the same straight line. Peob. XXI.—To draw tangentsto two given circles.1st Jfethod (fig.110).—Draw thestraight line ABCthrough the cen-iig. no. tres of the two … GEOMETRICAL PROBLEMS. given circles; from tlie centres A, B, draw parallel radii A D, B E, inthe same direction; join D E, and produce it to meet the centre line at C,and from C draw tangents to one of the circles by Prob. XIX. Those tan-gents will tonch hoth circles, as required. ^Id 2fethod (fig.…
