Practical draughtsmen's work, with numerous engravings and diagrams (1903)
Hasluck, Paul N. (Paul Nooncree), 1854-1931, ed · Philadelphia, D. McKay · leaf 24
Fig. 15.—Framed Set Square. Fig. 16.—Set Square for Lettering. squares, made of plain pieces of thin mahogany, pear-tree, orother woods, planed to the required angles, are liable to twistand warp when exposed to heat or dampness. These squares have a hole, about | in. in diameter, borednear the…
Mechanical drawing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
