Tonnelot Thermometer

This mercury-in-glass thermometer has a cylindrical bulb, and a milk white tube that is marked “Yale Observatory Standard No. 51 Made by Tonnelot à Paris Equal graduations Crystal glass tube made April 1879.” The scale, which extends from -4.8 to +104.6 degrees Centigrade, is graduated every degree, in fifths. The protective chrome case is marked “Yale Observatory Standard No 51.” It came to the Smithsonian from the U.S. Weather Bureau.
Ref.: Leonard Waldo, “Examination of Thermometers at the Yale Observatory,” Popular Science Monthly 18 (1881): 367-374.
Currently not on view
Object Name
date made
Tonnelot, Jules
place made
France: Île-de-France, Paris
ID Number
catalog number
accession number
Measuring & Mapping
Thermometers and Hygrometers
See more items in
Medicine and Science: Physical Sciences
Thermometers and Hygrometers
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
U.S. Weather Bureau

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