Signedswitchboard marked: H.W. Sullivan London.
side of case marked: Imported by James G. Biddle Philadelphia
Inscribedon instrument: Harvard University 497
twice marked: Property of Harvard Engineering School
FunctionA potentiometer is an instrument for measuring the potential (voltage) in a circuit. Before the introduction of the moving coil and digital volt meters, potentiometers were used in measuring voltage, hence the '-meter' part of their name. The method was described by Johann Christian Poggendorff around 1841 and became a standard laboratory measuring technique.
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ProvenanceFrom the Harvard University Engineering School, 11/56.