Keuffel & Esser Telescopic Alidade

This alidade has an inverting telescope, striding level, vertical arc reading 30 degrees each way, and separate trough compass. It is part of a complete plane table outfit that Keuffel & Esser described "as made for the U.S. Coast and Geodetic Survey" and sold for $175. The Survey acquired this example in 1893. The signatures read “KEUFFEL & ESSER CO. NEW YORK CHICAGO 2447" and "U.S.C.&G.S. No. 91.”
Ref: Keuffel & Esser, Catalogue (New York, 1906), p. 408.
Currently not on view
Object Name
alidade (telescopic)
Keuffel & Esser Co.
telescope: 10 in; 25.4 cm
objective; aperture: 1 in; 2.54 cm
ID Number
catalog number
accession number
Measuring & Mapping
Surveying and Geodesy
See more items in
Medicine and Science: Physical Sciences
Surveying and Geodesy
Data Source
National Museum of American History, Kenneth E. Behring Center
Keuffel & Esser. Catalogue of Keuffel & Esser Co., 32 Edition

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