Casella Theodolite

Description
This instrument is marked "L. Casella, Maker to the Admiralty & Ordnance LONDON 5227" and "U.S.C.&G.S." It was made between 1878, when the U. S. Coast Survey became the U. S. Coast and Geodetic Survey, and the death of Louis Casella in 1897. Casella termed it a "Travellers' Transit Theodolite . . . with telescope in centre, much used by the Indian Government, as well as by the United States Coast Survey." With carrying case, it weighed 5.25 pounds and cost £19.10.0. The horizontal and vertical circles are silvered, and read by verniers and magnifiers to single minutes.
Refs: L. P. Casella, List of a Few Instruments in General Use, Selected from the General Catalogue of Standard Meteorological and Other Instruments for Observatories, Travelers and Explorers, and the Army and Navy (London, 1896), p. 25.
Location
Currently not on view
maker
Casella, Louis Paschal
place made
United Kingdom: England, London
Measurements
overall: 11 3/4 in; 29.845 cm
horizontal circle: 4 1/2 in; 11.43 cm
vertical circle: 4 1/2 in; 11.43 cm
telescope: 11 in; 27.94 cm
needle: 1 7/8 in; 4.7625 cm
overall: 12 1/4 in x 5 3/4 in x 11 5/8 in; 31.115 cm x 14.605 cm x 29.5275 cm
ID Number
PH.309657
catalog number
309657
accession number
106954
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Surveying and Geodesy
Data Source
National Museum of American History, Kenneth E. Behring Center

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