Collimating the inner tower at Station Winnie.
Collimation involved placing the observing instrument directly over the mark.
Triangulation party of Carl I. Aslakson
Image ID: theb2537, NOAA's Historic Coast & Geodetic Survey (C&GS) Collection
Location: Itasca County, Minnesota
Photo Date: August 21, 1934
Credit: Captain Ray Tryon, C&GS
Category: Geodesy/Triangulation/Towers/Bilby Steel/
• High Resolution Photo Available