Maximum Thermometer

Maximum Thermometer

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This thermometer is so designed that an air bubble separates a small amount of mercury from the main part of the column. When the instrument is mounted horizontally, the detached mercury remains in place when the rest of the column falls, thereby indicating the maximum temperature. John Phillips, an English geologist, introduced the form at the 1832 meeting of the British Association for the Advancement of Science. In 1856 he showed an improved form made by Louis P. Casella of London.
Appleton's Encyclopaedia noted in 1860 that James Green of New York "appears to have removed the objections to the previous forms of the maximum thermometers, and produced a highly simple and perfect instrument." Henry J. Green, who was James Green's nephew and successor, also made instruments of this sort. This example has a grooved aluminum plate that is marked "H. J. GREEN B'KLYN. N.Y." and "NO. 9746 U. S. WEATHER BUREAU" and "MAXIMUM." The plate is graduated every 5 degrees Fahrenheit from -20 to +125. The bulb is spherical. The stem is marked "U.S. 9746" and is graduated every degree F. from -22 to +126. It was made between 1890 (when H. J. Green moved his business to Brooklyn) and 1904 (when it came to the Smithsonian).
Ref.: Henry J. Green, Meteorological and Scientific Instruments (Brooklyn, 1900), p. 22.
Currently not on view
Object Name
date made
ca 1900
H. J. Green
place made
United States: New York, Brooklyn
overall: 11 in; 27.94 cm
overall; thermometer: 12 1/8 in x 15/16 in x 3/8 in; 30.7975 cm x 2.38125 cm x.9525 cm
overall; parts in box: 2 in x 3 in x 13 5/8 in; 5.08 cm x 7.62 cm x 34.6075 cm
ID Number
catalog number
accession number
Credit Line
U.S. Weather Bureau
See more items in
Medicine and Science: Physical Sciences
Thermometers and Hygrometers
Measuring & Mapping
Data Source
National Museum of American History
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