1913: Mass production of glass
Historical evidence of glass making was found dating back to 3500B.C. in Mesapotamia.In the the late 1890’s, Colburn visited the glass-bottle factory developed by Michael Owens. Colburn began experimenting with methods for producing continuous flat glass disks, which led to him getting a patent in 1906. The Toledo Glass Company purchased the patents in 1912, whom Colburn worked with to improve the process. In 1913, flat sheet glass production became commercially viable for the first time. The Toledo Glass Company eventually evolved into the Libby Owens Ford glass company, providing glass for automobile production. In 1931, they produced the dual-pane windows for the Empire State Building, and in 1946 opened a Thermopane (insulated glass) plant. The Libby Owens Ford company was purchased by Pilkington, Ltd. in 1985, one of the world’s leaders in architectural glass.  `Note: The 6,514 windows for the Empire State Building were replaced/rebuilt in 2010, increasing the R-value of the windows from R-2 to R-values ranging from R-5 to R-8.