Circular slide rule, American, 1942-1945.

Flour calculating slide rule, c 1910.

Boxwood Coggeshall folding slide rule, 1720-1730.

McFarlane calculating cylinder, 19th century.

Spiral slide rule, 1663.

Excise Officer's slide rule, 1759-1769.

Henry Sutton's slide rule, 1663.

Ullage slide rule, 1759-1776.

Navigation slide rule, c 1800.

Navigation slide rule, c 1800.

Bate's interest scale, 1824.

Bate's interest scale, 1824.