Thomson-Rice Voltmeter, 1888

Nineteenth-century scientists and electrical engineers devised various types of meters to monitor and measure electrical output. Voltmeters, ammeters, and wattmeters became vital tools in the generation and distribution of electrical power, as well as scientific experimentation. Elihu Thomson, a prolific inventor and co-founder of the Thomson-Houston Electric Company, along with E. W. Rice developed this accurate and affordable voltmeter.