Negretti & Zambra Recording Thermometer

Description
Negretti & Zambra introduced this type of instrument in 1874. The stem is U-shaped, with a small U-shaped bend just above the cylindrical bulb. In use, the thermometer would be hung with the bulb down. Rotating it one full turn causes the mercury in the first half of the tube to flow into the second half, thereby recording the temperature at that moment. In use, it might be connected to a clock that would rotate it at a scheduled time.
In this example, the mercury-in-glass thermometer is mounted on an ebony plate marked "NEGRETTI & ZAMBRA LONDON" and "RECORDING THERMOMETER." A white porcelain strip on the plate is marked "NEGRETTI & ZAMBRA'S PATENT" and graduated every 5 degrees Fahrenheit from 0 to 120; a second graduation runs from 20 to +120. The back of the stem is milk white. The front, on the side nearer the bulb, is marked "PATENT No. 28" and graduated (but not numbered) every degree Fahrenheit from 0 to +120; the other side is graduated (but not numbered) every degree from +15 to +120.
Ref.: Negretti and Zambra, Encyclopaedic Illustrated and Descriptive Reference Catalogue (London, after 1878), pp. 101-103.
Location
Currently not on view
Object Name
recording thermometer
thermometer
maker
Negretti & Zambra
place made
United Kingdom: England, London
ID Number
PH*317478
accession number
230396
catalog number
317478
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Thermometers and Hygrometers
Data Source
National Museum of American History, Kenneth E. Behring Center

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