Test of Steel Truss Bridge with Locomotive Loading | University of Illinois Archives
Sepia-toned photograph showing test of a steel truss bridge in White Heath, IL with locomotive loading. The caption notes that slight changes in the bridge's form, in its posts and chords, were measured with special micrometers. The two unidentified men on the scaffolding were measuring the compression in a vertical post.
Found in RS 11/1/10, Vol. 4
Image measures 16.7 x 11.2 cm