USGS Multimedia Gallery
Title: Explorer's Alidade
Description: Manufactured by Keuffel & Esser, New York & New Jersey. In this type of alidade, as opposed to the high standard, the telescope mounted close to the straightedge, producing a more compact instrument. A right-angle prism is attached to the eyepiece and permits viewing by looking down. A cylindrical bubble and magnetic compass needle are attached to the base; these are used to level and orient the plane table to its proper position. Object ID: USGS-000161
Photographer: USGS Museum Staff , U.S. Geological Survey
Usage: This image is public domain/of free use unless otherwise stated. Please refer to the USGS Copyright section for how to credit the photo.
USGS Museum Collection
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