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 29
isagree, the ruler is inaccurate. When one rulerhas been tested, the other can be examined by placing their edges againstthe correct one, and holding them between the eye and the light. Triangles are made of the same kinds of wood as the ruler, and some-what thinner, and of various sizes. They… … Fig. 35. long on the side is convenient for making drawings to a large scale. Cir-cular openings are made in the body of the triangle for the insertion of theend of the finger to give facility in sliding the triangle on the paper. Tri-angles are sometimes made as large as 15 to 18 inches on the…
