# Quadrant-electrometer with calibration, after Abraham Brook

In the first century after the discovery of static electricity it appeared to be very difficult to determine the magnitude of an electric charge or an electric potential. One of the first to make an instrument with which the magnitude of an electric charge or voltage could be measured, was Abraham Brook. The instrument shown here consists of two instruments which can be used separately or together. The two moving, horizontal arms can be used to calibrate the dial electrometer. For this, the repulsive force, caused by an electric force applied to the spheres, is measured. This force is measured by means of a rider, that can slide over the arm with a scale in grains, with 1 grain being approximately 60 milligram (see also 550). When an electric charge is applied to the vertical pair of arms, the repulsive force of the spheres on that arms is transferred to the dial and the movement can be read in degrees.

Fysisch Kabinet

Title

Quadrant-electrometer with calibration, after Abraham Brook

Translated title

Quadrant-electrometer with calibration, after Abraham Brook

Creator

[{'date_of_birth': u'', 'role': u'', 'qualifier': '', 'date_of_death': u'', 'creator': 'George Adams, London'}]

Production notes

1785

Material

[{'material': 'Glass'}, {'material': 'brass'}]

Object number

FK 0548

Reproduction reference

[{'reference': '..\\images\\Fysisch\\Gekoppelde afbeeldingen\\FK 0548.jpg'}]