Leoni Mercury Wheel Barometer

The large circular face is silvered, and marked ‘LEONI’S IMPROVED” and “114 JOHN ST / New York / WARRANTED.” The scale around the circumference extends from 28 to 31 inches, and is subdivided to 0.01 inch; there are also markings for “Stormy,” “MUCH RAIN,” “Change,” “FAIR,” “SET FAIR,” and “Very Dry.” The mercury-in-glass thermometer at the top is mounted on a silver plate carrying a scale that extends from -20 to +120 degrees Fahrenheit, with indications for “FREEZING,” “TEMPERATE,” “SUMR HEAT,” BLOOD HEAT,” and “FEVER HEAT.” The case is rosewood veneer over pine. George Leoni worked in New York in the 1840s, advertising as “Importer and Manufacturer of Mathematical and Philosophical Instruments, &c.”
Ref: George Leoni, Ample Instruments for the Barometer and Thermometer (New York, 1841).
Currently not on view
Object Name
barometer, mercury
date made
Leoni, George
place made
United States: New York, New York
ID Number
accession number
catalog number
Measuring & Mapping
See more items in
Medicine and Science: Physical Sciences
Data Source
National Museum of American History, Kenneth E. Behring Center

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