In the 1770s, scientists developed eudiometers for determining the goodness (or rather, the oxygen content) content of samples of air. The most successful form, described by Alessandro Volta in 1777, used an electric spark to ignite the air to be tested.
Building on Volta’s work, the American chemist, Robert Hare (1781–1858), developed an “aqueous sliding-rod hydro-oxygen eudiometer.” This replica of Hare’s instrument was made in anticipation of the opening of the National Museum of History and Technology in 1964.
Ref: Robert Hare, “An Account of Some Eudiometers of an Improved Construction,” The Philosophical Magazine and Journal 67 (1826): 21–30.
Robert Hare, A Compendium of the Course of Chemical Instruction in the Medical Department of the University of Pennsylvania<.i> (Philadelphia, 1840), pp. 176-177.
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