Amsler Type 2 Polar Planimeter Sold by Crosby Steam Gage & Valve

This German silver instrument has a 4" arm with tracer point and 6" pole arm with short cylindrical weight. The arm lengths are fixed. The tracer arm and pole arm are connected by a hinge and form a circle around the measuring wheel, vernier, and registering dial when the instrument is closed. The top of the pole arm is marked in script: Crosby Steam Gage & Valve Co. Boston. The top of the weight is marked: 16378 (/) 10 [square] in. A serial number is marked underneath the tracer arm and the weight: 10259.

A wooden case is covered with black leather and lined with purple velvet. The top of the case is marked: CROSBY STEAM GAGE & VALVE C^o (/) BOSTON.

To measure the areas of diagrams produced by its steam engine indicators, Crosby imported and sold Amsler polar planimeters of types 1, 2, and 3. The presence of a registering dial and the screw thread on the post extending from the measuring wheel indicates that this example is a type 2. Planimeter expert Joachim Fischer dated this object to about 1882. Charles W. Batchelor (1845–1910), the father of the donor, used it in his work as one of Thomas A. Edison's chief assistants. For instance, between 1884 and 1888, he managed the Edison Machine Works, where a planimeter may have been especially useful. From 1888 to at least 1907, Crosby sold the Amsler type 2 in a case for $25.00. For information on Amsler and his invention, see 1987.0107.10. Compare to 1989.0305.01.

This instrument was received by the Smithsonian in 1960.

References: Crosby Steam Gage & Valve Co. Catalogue (Boston, 1888), 104–109; Crosby Steam Gage & Valve Co. Catalogue (Boston, 1900), 170–176; Crosby Steam Gage & Valve Co. Catalogue (Boston, 1907), 203–210; Crosby Steam Gage & Valve Company, Practical Instructions Relating to the Construction and Use of the Steam Engine Indicator (Boston, 1911), 43–46, 83–86; Craig Bliss, The Crosby Steam Gage & Valve Co., http://www.crosby-steam.com/index.htm.

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