Regnault Hygrometer

Regnault Hygrometer

<< >>
Usage conditions apply
Henri Victor Regnault, professor of physics at the College de France in Paris, described this type of instrument in 1845. It consists of a brass stand; a silver tube into which ether is poured and through which air can be made to pass; a thermometer to take the temperature of the ether; and another to measure the ambient air.
This example has two mercury-in-glass thermometers, each of which has a milk-white back marked "Jas. Green. 175 Grand St. New York." The clear front of one is graduated every ½ degree Fahrenheit from -15 to +130. The clear front of the other is graduated every degree Fahrenheit from -10 to +120. It was made between 1849 and 1875 when James Green was working at this address in New York City. It came to the Smithsonian from the U.S. Military Academy.
Ref: H. V. Regnault, "Études sur l'hygrométrie," Annales de Chimie et de Physique 15 (1845): 129-236, on 196-201.
Negretti & Zambra, Treatise on Meteorological Instruments (London, 1864), pp. 104-105.
Currently not on view
Object Name
Regnault hygrometer
date made
Green, James
place made
United States: New York
overall in box: 2 in x 13 3/4 in x 4 1/2 in; 5.08 cm x 34.925 cm x 11.43 cm
ID Number
accession number
catalog number
Credit Line
U.S. Military Academy
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Thermometers and Hygrometers
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.


Add a comment about this object