Spy Glass

Description
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.
Location
Currently not on view
Object Name
telescope, pocket
date made
1775-1800
maker
Jesse Ramsden
Physical Description
brass (overall material)
glass (overall material)
shagreen (overall material)
paper (overall material)
Measurements
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
1991.0664.0905
accession number
1991.0664
catalog number
M-06301
collector/donor number
SAP 993
catalog number
1991.0664.0905
subject
Pharmacy
See more items in
Medicine and Science: Medicine
Art
Health & Medicine
European Apothecary
Data Source
National Museum of American History, Kenneth E. Behring Center

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