Optical Flat for a Spherometer

An optical flat is a disc of heavy glass made perfectly flat that is used to zero out a spherometer before use in order to assure the device produces an accurate reading. A spherometer is a small device used primarily for measuring the curvature of objects such as lenses and curved mirrors. For further information about spherometers, see object MA*315739. This flat accompanies spherometer 2001.0217.07.
Currently not on view
Object Name
optical flat
date made
ca 1800s
Physical Description
glass (overall material)
overall: 1.3 cm x 10.8 cm x 10.8 cm; 1/2 in x 4 1/4 in x 4 1/4 in
ID Number
catalog number
accession number
Science & Mathematics
See more items in
Medicine and Science: Physical Sciences
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of Department of Physics and Astronomy, Bowdoin College
Additional Media

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