Repsold Universal Instrument

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This instrument is marked "A. Repsold & Sohne, Hamburg, 1874" and "U S C S No. 17." The U. S. Coast Survey bought it in 1874, just a few years after Cleveland Abbe had introduced Americans to the similar instrument that he had seen at the Pulkova Observatory in Russia. Abbe noted that it "offers itself to us as an instrument equally applicable in all latitudes to the determination of latitude, and fit for the determination of time for secondary stations between 70° of latitude and the equator, if accurately constructed as by Repsold, and used so as to eliminate constant or systematic errors. By reason of the ease with which it is put in position, and the brightness of the stars observed, as well as by the accuracy of its divided circles, level and microscopes, there is no time lost nor money expended in building stations, nor in waiting for nightfall, nor in tedious repetition of observations." The instrument that Abbe described had two vertical circles; the Coast Survey instrument has only one.
Johann Georg Repsold (1771–1830) established a small shop in Hamburg around 1799 and began making precision instruments for astronomy and geodesy. In 1831, shortly after Repsold's death, his sons Georg (1804–1885) and Adolf (1806–1871) began trading as A. & G. Repsold. In 1867, when Georg retired and Adolf's two sons joined the firm, the name was changed to A. Repsold & Sohne. In his 1882 price list of important astronomical instruments, Elias Loomis noted that "Astronomical instruments of the first class are made by several other manufacturers in Europe, particularly by A. Repsold and Son, of Hamburg, Germany; but the latter firm does not publish a catalogue, and it is necessary to make a special contract for such instruments as may be required." This problem notwithstanding, Repsold instruments were fairly well known in the United States. The Repsold firm came to an end in 1919.
Refs: Cleveland Abbe, "The Repsold Portable Vertical Circle," American Journal of Science 43 (1867): 207–216, 309–315.
Elias Loomis, An Introduction to Practical Astronomy (New York, 1882), p. 505.
J. A. Repsold, Vermehrte Nachrichten über die Familie Repsold (1896).
Currently not on view
A. Repsold & Sohne
place made
Deutschland: Hamburg, Hamburg
overall: 25 1/2 in x 22 in x 22 in; 64.77 cm x 55.88 cm x 55.88 cm
ID Number
accession number
catalog number
Credit Line
U.S. Coast and Geodetic Survey
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Medicine and Science: Physical Sciences
Measuring & Mapping
Surveying and Geodesy
Data Source
National Museum of American History


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