Calorimotor (Replica)

The work of Luigi Galvani in the early 1790s led other scientists to experiment with galvanic electricity and develop ever more powerful batteries. Allesandro Volta introduced the electric pile. The trough battery designed by William Cruickshank was essentially a Voltaic pile turned on its side. Humphry Davy used large batteries to isolate new elements. James Woodhouse, an American chemist who went to England and returned home with a Cruickshank battery, shared his enthusiasm for galvanic work with Robert Hare (1781–1858), his student at the University of Pennsylvania.
As professor of chemistry in the Medical Department of the University of Pennsylvania, Hare developed what was widely regarded as the best equipped lecture room in the world, and demonstration experiments suitable for very large classes. His galvanic instrument, introduced in 1817, consisted of 20 copper plates that connected with one another, 20 zinc plates that connected with one another, and a wooden box filled with a weak acid. It generated heat as well as electricity, and so Hare called it a calorimotor.
The calorimotor that Hare gave the Smithsonian in 1848 was destroyed in the Institution’s fire of 1865. The replica shown here was made in anticipation of the opening of the National Museum of History and Technology in 1964.
Ref: Robert Hare, A New Theory of Galvanism supported by some Experiments and Observations made by means of the Calorimotor (Philadelphia, 1819).
Robert Hare, “A New Theory of Galvanism, supported by some Experiments and Observations made by means of the Calorimotor,” American Journal of Science 1 (1819): 413-426, and plate.
“Dr. Hare’s Calorimotor,” in Benjamin Pike, Jr., Illustrated Descriptive Catalogue of Optical, Mathematical, and Philosophical Instruments (New York, 1856), vol. 1, pp. 328-330.
Currently not on view
Object Name
date made
early 1960s
Hare, Robert
Physical Description
wood (overall material)
copper (overall material)
steel (overall material)
overall: 46 in x 22 in x 25 in; 116.84 cm x 55.88 cm x 63.5 cm
ID Number
catalog number
accession number
See more items in
Medicine and Science: Chemistry
Science & Mathematics
Data Source
National Museum of American History, Kenneth E. Behring Center


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