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Pair of 6-inch brass callipers with sector, by Thomas Heath in pocket leather case Pair of 6-inch brass callipers with sector, by Th Mathematics 1720-1753

Parallel rule, 6-inch, ivory and electrum, ordinary pattern, (single parallelogram) Parallel rule, 6-inch, ivory and electrum, ordinar Mathematics 1876

Pocket case of drawing instruments (incomplete) by Dollond in green shagreen case (B517; A49993) Drawing instrument set Mathematics