Winlock & Huddleston Psychrometer

Winlock & Huddleston Psychrometer

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This is the model that Joseph Winlock, a professor of astronomy at Harvard College, and John S. F. Huddleston, a thermometer and barometer maker in Boston, submitted along with their patent application in 1873. The wet bulb thermometer is mounted on a brass plate that is marked "HUDDLESTON BOSTON" and graduated every degree Fahrenheit from +10 to +115. The dry bulb thermometer is missing.
The wooden tower holds a rotating chart that indicates relative humidity, and carries a brass plate graduated every degree from +6 to +113. The patent described "a simple, efficient, and convenient means of determining the relative humidity of the atmosphere or the dew-point, so called, without calculation."
Ref: J. Winlock and J. S F. Huddleston, "Psychrometer," U.S. Patent 149176 (issued 1874).
Currently not on view
Object Name
Object Type
Patent Model
date made
Huddleston, John S. F.
Winlock, Joseph
place made
United States: Massachusetts, Boston
overall: 14 3/4 in x 8 1/2 in x 4 in; 37.465 cm x 21.59 cm x 10.16 cm
ID Number
catalog number
accession number
patent number
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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