Cylindrical Beetz-type Electroscope (early 1900s)

This is a cylindrical electroscope for qualitative demonstrations of electrostatic phenomena. That it was manufactured in Czechoslovakia is indicated by the following inscription on the condenser plate: F. KMENT PRAHA.

Electroscopes employing a cylindrical design like this one are often attributed to W. Beetz. For example, the 1908 Philip Harris catalog refers to a similar electroscope as follows: “Electroscope, Beetz’s form.”

The body is made of brass, the condenser plate is steel, and the insulator for the brass conduction rod is amber.

The two aluminum leaves at the bottom of the conducting rod are separated by a vertical plate which prevents them from touching each other. This feature permits the electroscope to be operated with either one or two leaves.

The supporting post beneath the body of the electroscope employs glass which would seem to insulate the electroscope from the base. The reason for doing so is not obvious (to me anyway).

A device known as an electrophorus would be used to transfer a charge to the condenser plate on the top. For an explanation of how an electroscope can be charged and how an electrophorus works, click here.

For additional information check out our other Beetz-type electroscope.

Size: ca. 13” tall. The chamber is 4" in diameter and 3.25" deep


Philip Harris and Co., Ltd. An Explanatory Price List of Physical Instruments for Experimental Science. 1908


Electroscopes               Museum Directory

Last updated: 07/25/07
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