pl23_theb3904.jpg
![Heliotrope used for directing sun's rays to distant observer theb3904.jpg Heliotrope used for directing sun's rays to distant observer](https://s3.amazonaws.com/s3-east-testmedia-noaa.woc.noaa.gov/dam/Photos/legacy/pl23_theb3904.jpg)
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
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.