Telescopic Alidade

(Credit: USGS Museum Staff, U.S. Geological Survey. Public domain.)

Detailed Description

A high standard alidade; this type of alidade permits direct viewing through the telescope. The level is mounted below the inverting telescope and the base (blade) is solid brass with circular voids. Manufactured by Keuffel & Esser, New York & New Jersey. Object ID: USGS-000165

Details

Image Dimensions: 1672 x 1024

Location Taken: US