Humboldt State University ® Department of Chemistry
Robert A. Paselk Scientific Instrument Museum
Reflecting Galvanometer Scale with Lamp and Stand
Leeds & Northrup Co.
Humboldt State College; 1960
This is an accessory to go with the L & N Reflecting Galvanometers-it replaces a scale and telescope. In use the lamp projects an image of an arrow pointer which reflects off of the mirror of the galvanometer and back to the glass scale, thus providing a meter scale with a very long (one meter) effective needle length. This in turn gives the galvanometer a greater readability, and by keeping the mass and inertia of the actual moving element low, a greater sensitivity.
This instrument was used by students in the physical/analytical chemistry laboratory at HSU for sensitive measurements in conjunction with the L&N Type R reflecting galvanometer.
The heavy, cast iron, triangular base has a single chromed-brass, knurled, leveling screw on the front point. The base holds a single half inch rod vertically in a heavy sleeve, clamped with a knurled sleeve and collet. The lamp housing is of cast heavy aluminum construction with a chromed thumbscrew clamp holding it onto a bent rod which in turn is clamped to the tripod base with a black painted brass right angle clamp. The lens holder of the lamp is constructed of chromed brass sleeve with a double convex lens at the end, which slides over a second tube for focusing.
This instrument is illustrated and described on p743 of the Cenco 1960 Catalog (J-300). An earlier version with a tripod bas is described on p 1286 of the 1950 Cenco Catalog (J150).