Spy Glass

Lenses at each end made faraway things look closer, so a sailor or soldier could study distant ships or land.

Date: 1775-1800
Maker: Jesse Ramsden
Place: United Kingdom: England, London
Materials: brass (overall material); glass (overall material); shagreen (overall material); paper (overall material)
Dimensions: overall: 12 cm x 4.2 cm; 4 23/32 in x 1 21/32 in; overall, case: 2 1/4 in x 5 5/8 in x 2 1/4 in; 5.715 cm x 14.2875 cm x 5.715 cm; overall, telescope: 1 5/8 in x 1 3/4 in x 4 3/4 in; 4.1275 cm x 4.445 cm x 12.065 cm
Museum: National Museum of American History
Credit line: Gift of American Pharmaceutical Association and Bristol-Myers Squibb Company

Small refracting telescope with an achromatic objective 1¼ inches aperture. There are two brass tubes. The inner one is engraved “Ramsden / London” and calibrated from one to four. A dial adjusts the eyepiece. The telescope is housed in a cylindrical cardboard container covered in shagreen.

Jesse Ramsden (1735-1800), a prominent maker of mathematical and optical instruments. began in business in 1762, and became a Fellow of the Royal Society of London in 1786.

The museum's own record (Smithsonian, National Museum of American History)