Catalogue. A.H. Abbott & co., manufacturers and importers of mathematical and surveying instruments and drawing materials of every description .. (1896)
Abbott, A. H., & co., Chicago. [from old catalog] · [Chicago] · leaf 162
No. RUBBER TRIANGLES. … 1445 1445. Hard Rubber Triangles, for roof pitches, 6 in set Set.$2 50
Drawing instruments
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
