Armour Research Foundation clay grinding machine, Illinois Institute of Technology, Chicago, Illinois, ca. 1950s Armour Research Foundation (U.S.) Clay--Extrusion Grinding machines From the attached press release: "Brainstorming by engineering economists at Armour Research Foundation of Illinois Institute of Technology uncovered methods of grafting clay raw material to reduce particle size of limestone and eliminate surface popping, or "spelling." This machine is used in a spooner's plant to mix clay and water, remove air from mixture, and extrude clay in cylindrical form." Photographer unknown. Date of photograph unknown. Date range listed is approximate. 1950-1959 Still image Black and white photograph image/tiff islandora:1001258 0360401-I3-10-003 http://hdl.handle.net/10560/islandora:1001258 Office of Communications and Marketing photographs, 1905-1999 Illinois Tech Libraries Illinois Institute of Technology en Chicago (Ill.) In Copyright http://rightsstatements.org/vocab/InC/1.0/