Harold McMaster invented tempered glass which is indispensible in modern skyscrapers and any construction where glass strength and safety is critical. McMaster studied physics at Ohio State University. He then became a research physicist at Libby-Owens-Ford Glass Company. McMaster later founded Permaglass, Inc. where he commercialized the glass tempering process. During his career, McMaster developed over 100 patents in the fields of glass bending and tempering, solar energy, and rotary engines. He died on August 25, 2003.