Measuring Stretches in Steel Stirrups in a Concrete Beam | University of Illinois Archives
Sepia-toned photograph showing an unidentified man using a strain gauge to measure small stretches in Reinforcing Stell Stirrups in a Concrete beam. The caption indicates that the gauge could detect changes in length of one ten-thousandths of an inch.
Found in RS 11/1/10, Vol. 4
Image measures 11.2 x 13.1 cm