From the attached caption: "Seymour A. Bortz, structural engineer in the ceramics and minerals research department at Armour Research... Show moreFrom the attached caption: "Seymour A. Bortz, structural engineer in the ceramics and minerals research department at Armour Research Foundation of Illinois Institute of Technology, investigates the flexural strength of a concrete specimen by means of electric strain gages and a hydraulic press." Photographer unknown. Date of photograph is unknown. Date range listed is approximate. Show less
