Electroscope of Cheneveau and Laborde (ca. 1910 - 1920)

This electroscope, based on the ideas of Pierre Curie,  was developed by C. Cheneveau and A. Laborde sometime around 1908, and was described in their publication  "Appareils pour la Mesure de la Radioactivite, d'Apres la Methode Electroscopique." Journal de physique, 4e série, tome VIII, Mars 1909, pages 161-174.  It undoubtedly served as the inspiration for the Lind electroscope.  Samuel Lind worked with Marie Curie and was almost certainly familiar with this design.
Like the Lind electroscope, the cylindrical body is made of steel, has a microscope mounted to it, and employs a wire screen against the inside of the glass sides to shield the leaf from the build up of a static charge.  

The electroscope is designed so that it can be connected to a separate interchangeable ion chamber. The design of the chamber would depend on the type of sample being analyzed, i.e, whether it was a solid or a gas. While the collection does not include any of these chambers, they would be very similar to the chambers used with the Lind electroscope. 

In the figure above right, the charging rod is seen coming in from the left side . When pushed, the end of the charging rod would press up against the slightly curved spring plate attached to the back (left) side of the vertical support rod. The aluminum leaf is missing in this example. Coming in from the right side (at the tip of the microscope) is the vertical cover plate that would be used to protect the leaf when the electroscope was being transported.  

 

In the photo to the right, the connector for attaching the separate interchangeable ionization chambers is seen pointing towards the lower right. 

The connection/attachment more or less in the bottom center of the photo has a hollow opening that leads to the inside of the chamber. At the outer opening of this connection are the remaining glass fragments of a  flask that was used to hold a desiccant (e.g., phosphoric anhydride). 

The following is engraved on the side of the electroscope body:  Societe Centrale de Prodts  Chimiques, 44 rue des Ecoles, Paris

I would like to express my thanks to Jean-François Loude for his assistance in identifying this electroscope and in providing the aforementioned reference.

Electroscopes               Museum Directory

Last updated: 07/25/07
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