A 90-foot Bilby tower wrecked by a storm.Triangulation party of Earl O. Heaton
3/18/2019 2:24:53 PM
Date: 1928
Credit: C&GS; Season's Report Heaton 1929
Location: Near Chariton, Iowa
Subject: Geodesy
Subject: Triangulation
Subject: Towers
Subject: Bilby Steel