Priced and illustrated catalogue of mathematical instruments...Swiss drawing instruments, transits, levels.. (1867)
McAllister, William Y · Philadelphia PA · leaf 26
MATHEMATICAL INSTRUMENTS. … 3370. This Square combines, in the most convenient form, five different instruments: m. The Try Square, the Mitre, the T-Square, the Graduated Rule, and (what la entirely new) the Centre-Square, for finding the centre of a circle. Fui 1 explains its application as a Centrb-Squarb. Put the…
Mathematical instruments
Internet Archive · Smithsonian Libraries · Public domain (published before 1931). Free to use for anything.
