Fuess Asperation Psychrometer

In the late 1880s, a German meteorologist named Adolph Richard Assmann designed an aspiration instrument with a fan to draw air past the wet- and dry-bulb thermometers of a common psychrometer. Assmann also enclosed the device in double-walled ducts of polished metal designed to minimize the effect of radiation. This form long remained in widespread use.
In this example, the clockwork housing is marked "R. Fuess / Berlin-Steglitz / No. 189500." The back side of the thermometer scales are marked "CENTIGRADE R. FUESS, BERLIN-STEGLITZ JENAER Normaliglas 16111."
Ref: R. Fuess, Liste D2 über Thermometer, Psychrometer, Hygrometer und Hypsometer (Steglitz bei Berlin, 1910), p. 6.
Currently not on view
date made
after 1891
R. Fuess
overall: 16 3/4 in; 42.545 cm
overall: 5 3/8 in x 16 5/8 in x 5 1/4 in; 13.6525 cm x 42.2275 cm x 13.335 cm
ID Number
catalog number
accession number
Credit Line
Freer Gallery of Art
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Thermometers and Hygrometers
Data Source
National Museum of American History


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