Tonnelot Thermometer

This mercury-in-glass thermometer has a cylindrical bulb. The tube is marked, in red, “Tonnelot à Paris (1884.5) 4289” and graduated from -10.2 to 108.0 degrees (Centigrade?). It is probably one of the very precise thermometers with a tube of extra-hard glass that was made by Tonnelot for the International Committee of Weights and Measures, tested at the Bureau International at Sèvres, and distributed to government organizations around the world. It came to the Smithsonian from the U.S. Weather Bureau.
Ref: J. A. Hall, “The International Temperature Scale Between 0 Degrees and 100 Degrees C,” Philosophical Transactions 229 (1930): 1-48.
Currently not on view
Object Name
Tonnelot thermometer
date made
ca 1884
Tonnelot, Jules
overall: 25 1/2 in; 64.77 cm
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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