In the early part of the 20th century, most apparatus makers supplied rugged versions of reflecting wall galvanometers for use on table tops. The movements were of the standard D'Arsonval design. The telescope and sighting telescope were mounted on a separate stand.
The Washington and Jefferson instrument is by Gaertner, the
Denison galvanometer by the Ziegler Electric Company of Boston, and the Denison
galvanometer with the long leg is an early piece of of Central Scientific
Company apparatus.
The portable reflecting galvanometer at the right is in the apparatus collection of Case Western Reserve University in Cleveland, Ohio, and was made by the Chicago Laboratory and Scale Company. In 1895 the company bought out the C.H. Stoelting Company of Chicago, and Stoelting was made the president of the new company. By 1912 the name had changed back to Stoelting. However, my 1912 Stoelting catalogue does not show this instrument. However, the very first catalogue of the new Leeds & Northrup company, published in 1903, shows an almost identical instrument, listed as a High Sensibility D'Arsonval Galvanometer, that sold for $40.00. This was $10.00 more than their standard high-sensitivity wall galvanometer. |
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