Smithsonian - National Museum of American History, Behring Center

Physical Sciences Collection - Surveying and Geodesy

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Transit - click to enlarge

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Catalogue number:

"Kolesch & Co. New York. 1796"

height 12.25 inches; horizontal circle 6 inches diameter; needle 4.5 inches; telescope 10.25 inches long; hanging level 5 inches

Kolesch & Co. advertised this as an Engineer's Transit, No. 7650. The horizontal circle is graduated every 20 minutes, and read by opposite verniers with celluloid reflectors to 30 seconds. There is a clamp and tangent to the telescope. New, it cost $160. Heinrich Adolph Kolesch (1855-1903) was a German immigrant who began in business in 1885, taking over the firm that had been founded by E. & G. W. Blunt. Kolesch & Co. was still using the Blunt dividing engine in 1925. The firm was incorporated in New York State in 1904, and dissolved in 1947.

Ref: Kolesch & Co., Illustrated Catalogue and Price-List (New York, 1913), pp. 228-229 for this type of instrument, and pp. 195 and 198 for the history of the firm.

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