Braddock Instrument Company
Swissvale, PA (Pittsburgh). Around 1939, Braddock Instrument Company created an engineering tool named the Vis-A-Graph to assist with the 3-D visualization of descriptive geometry, analytics, solid geometry and engineering drawings. The tool consisted of folding transparent plastic coordinate planes with XYZ coordinate planes labeled. The product information stated "Folding transparent planes present in admirable form an essential element which has been missing from our teaching in spatial relations. They reduce geometrical abstractions to experimental and manipulative bases." The Vis-A-Graph sold in university book stores for $1.50.
