Universal Magnetometer with Dip Circle

This instrument is marked "LUDW. TESDORPF STUTTGART NO 1810"; and "U.S.C.&G.S. No. 25." It combines a magnetometer, a declinometer, a dip circle, and a theodolite. It was designed by J. F. A. M. Eschenhagen, Director of the Prussian Magnetic Observatory at Potsdam, and made by Ludwig Tesdorpf in Stuttgart. The U.S. Coast and Geodetic Survey installed instruments of this sort in its several magnetic observatories in 1902, and used them to calibrate field instruments. This one was used at Sitka, Alaska.
Ludwig Tesdorpf began in business in 1861, specializing in instruments for astronomy and geodesy. American scientists could see Tesorpf instruments at the Columbian Exposition held in Chicago in 1893 and at the World's Fair held in St. Louis in 1904. By 1906 the firm had been acquired by Sartorius.
Ref: K. Haussmann, "Der Magnettheodolit von Eschenhagen-Tesdorpf," Zeitschrift für Instrumentenkunde 26 (1906): 2-15.
L. A. Bauer and J. A. Fleming, "Magnetic Observatories of the United States Coast and Geodetic Survey," Report of the Superintendent of the United States Coast and Geodetic Survey Showing the Progress of the Work from July 1, 1901, to June 30, 1902, Appendix No. 5, p. 330.
Currently not on view
Place Made
Deutschland: Baden-Württemberg, Stuttgart
Physical Description
metal (overall material)
overall: large container: 13 in x 16 1/2 in x 9 5/8 in; 33.02 cm x 41.91 cm x 24.4475 cm
overall: medium container: 7 3/4 in x 16 in x 8 1/8 in; 19.685 cm x 40.64 cm x 20.6375 cm
overall: small container: 1 in x 19 in x 1 1/2 in; 2.54 cm x 48.26 cm x 3.81 cm
ID Number
accession number
catalog number
Credit Line
U.S. Department of Commerce, Coast & Geodetic Survey
Science & Scientific Instruments
Science & Scientific Instruments
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Science & Mathematics
Data Source
National Museum of American History


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