Mechanical movements, powers and devices; a treatise describing mechanical movements and devices used in construcive and operative mechinery and the mechanical arts, being practically a mechanical dictionary (1917)
Hiscox, Gardner Dexter, 1822?-1908 · New York : The Norman W. Henley publishing co. · leaf 374
1530. PERSPECTIVE CENTRO. — LINEAD.—The edges of legs on the sides a^ b, and c must be in line with their common 1 czzi axis, with clamp screws to hold the movable legs in their set position. The directing pins b and c should be set on the radial lines of the back point of the perspective, when the…
Mechanical movements
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.