Psychrometer
date: label: date made
content: 1885-1890
label: date made
content: ca. 1890
name: label: maker
content: H. J. Green
notes: label: Description
content: A psychrometer determines humidity by measuring the cooling effect of evaporation. This example has two mercury in glass thermometers, Each mounted a silvered brass plate, and the whole mounted on a wooden board. The plate holding the wet-bulb thermometer is marked "No. 1868 SIGNAL SERVICE U.S. ARMY" and the plate holding the dry-bulb theremometer is marked "H.J. GREEN, N.Y" and "No. 3070 SIGNAL SERVICE U.S. ARMY."
label: Description
content: The Signal Service maintained a national weather service from 1870 until the establishment of the U.S. Weather Bureau in 1891. This instrument was made after 1885 when James Green retired and his nephew, Henry J. Green, went into business on his own; and it was probably made before 1890 when H.J. Green relocated to Brooklyn. The Weather Bureau transferred it to the Smithsonian in 1904.
label: Description
content: Ref.: Henry J. Green, <i>Meteorological and Scientific Instruments</i> (Brooklyn, ca. 1890), p. 30.
label: Location
content: Currently not on view
place: label: place made
content: United States: New York, New York City
setName: label: See more items in
content: Medicine and Science: Physical Sciences
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content: Military
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content: Measuring & Mapping
creditLine: label: Credit Line
content: U.S. Weather Bureau
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.230007
label: catalog number
content: 230007
label: accession number
content: 42625
objectType: label: Object Name
content: Psychrometer
physicalDescription: label: Measurements
content: overall: 2 1/2 in x 6 1/2 in x 12 5/8 in; 6.35 cm x 16.51 cm x 32.0675 cm
label: Measurements
content: overall: 2 1/2 in x 7 in x 13 in; 6.35 cm x 17.78 cm x 33.02 cm