Collimating a 100-foot tower over the station mark. This is basically centering the observing stand on the interior of the tower over the station mark so that angle observations are made directly over the mark.

Image ID: cgs00314, NOAA's Historic Coast & Geodetic Survey (C&GS) Collection
Location: California, Palo Alto
Photo Date: 1932 March
Photographer: Mr. Floyd Risvold, USC&GS


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