Morin Altitude and Azimuth Instrument

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This instrument and its mate would have been used, at either end of a base line, to observe air borne objects, primarily for military or meteorological purposes. The Signal Corps of the U. S. Army acquired the pair around the time of World War I, and transferred them to the Smithsonian in 1923.
The beveled edge of the horizontal circle is graduated metrically to 400 grads, and read by opposite verniers to 1/20th of a degree. The vertical circle is graduated and read in the same way. A smaller telescope is mounted below the baseplate. The primary telescope is "broken," and thus the eyepiece remains at the same height regardless of the elevation of the objective. H. Morin began in business in Paris in 1880, making a variety of mathematical instruments. The firm was still in business in 1954.
Currently not on view
H. Morin
place made
France: Île-de-France, Paris
horizontal circle: 6 1/4 in; 15.875 cm
vertical circle: 5 1/2 in; 13.97 cm
telescope objective aperture: 1 1/2 in; 3.81 cm
overall: 11 1/2 in x 12 5/8 in x 7 3/4 in; 29.21 cm x 32.0675 cm x 19.685 cm
ID Number
catalog number
accession number
Credit Line
War Department, Signal Corps, Meteorological Section
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Medicine and Science: Physical Sciences
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Surveying and Geodesy
Data Source
National Museum of American History