Slide rule, 1815. Made by W Cary. Slide rul

Slide rule, 1815. Made by W Cary. Slide rul

Leadbetter slide rule, c 1700. Leadbetter s

Hayward's slide rule, 19th century. Made by

Combined circular and spiral slide rule, in a wooden frame, 1882.

Carpenter's slide rule, 1825-1860.

Carpenter's slide rule, 1825-1860.

Bate's ready reckoner, 1824. Slide rule mad

Exercise officer's slide rule, c 1700. Exer

George Fuller's spiral slide rule, no 849, c 1880.

Two slide rules, 1663 and 1881.

Bisaker's slide rule, 1654, and Thacher's calculating instrument, 1881.