Spy Glass

This short refracting telescope consists of two brass tubes. The inner one is engraved “Ramsden/London” and calibrated from one to four. The objective lens, 1 ¼ inches aperture is achromatic. There is a dial [not yet understood] that adjusts the eyepiece. The telescope is housed in a cylindrical cardboard container covered in shagreen.
Jesse Ramsden (1735-1800) was a prominent maker of mathematical and optical instruments who began in business in 1762, and was elected a Fellow of the Royal Society of London in 1786.
Currently not on view
Object Name
telescope, pocket
date made
Jesse Ramsden
Physical Description
brass (overall material)
glass (overall material)
shagreen (overall material)
paper (overall material)
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
place made
United Kingdom: England, London
ID Number
accession number
catalog number
collector/donor number
SAP 993
catalog number
Health & Medicine
European Apothecary
See more items in
Medicine and Science: Medicine
European Apothecary
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Bristol-Myers Squibb Company
Related Publication
Warner, Deborah Jean. Telescopes For Land And Sea
Urdang, George and Ferdinand William Nitardy. The Squibb Ancient Pharmacy: A Catalogue of the Collection
Additional Media

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