Electrostatic Voltmeter
French, 1877-1950

This is essentially a scale for "weighing" electricity. A voltage source is attached, one pole to each plate. The electrostatic field between the two plates pulls them together, and in the center of the left plate there is a spring scale that measures the force of this pull. With proper calibration, this directly gives the voltage.

A meter of this sort can measure very high voltages, without drawing a significant electrical current.

Below are shown two different forms of electrostatic balance, extracted from George Adams' 1792 Essay on Electricity ... (4th edition). The upper left is a simple balance scale, just like the "scales of justice".

The balance below acts in a manner similar to the Henley Electrometer.

Museum Hours: Tuesday - Saturday 10 to 5
Thursdays 10 am to  8pm 
Closed Major Holidays
Library Hours: Monday - Friday 9 to 4:30

Admission: $7 Adults; $5 Students & Seniors; Children 3 and under are FREE!

© The Bakken Updated: April 6, 2007