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pl23_theb3904.jpg

Heliotrope used for directing sun's rays to distant observer

Image

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Permalink

https://www.noaa.gov/media/digital-library-photo/pl23theb3904jpg

Description

Heliotrope used for directing sun's rays to distant observer.Used to illuminate station site so far distant observer could measure angles

Collection

Historic Coast & Geodetic Survey

Keywords

Geodesy

Instruments