Innovation: Insulated glass
By: C.D. Haven
For thousands of years, single pane glass blocked the wind, but allowed heat and cold to pass thru it easily.
Thomas Stetson invented and patented insulated glass in 1865, but did not get much use in the building industry until 1930, when C.D. Haven (U.S.) made insulated glass commercially available, calling it Thermopane. It was commonly available by 1950 (post WWII) .
Insulated glass provides increased thermal and sound insulation (though still only a fraction of what a wall provides). This innovation eventually led to more research and development into ways of increasing the insulation properties of glass, and into methods of reducing the transmission of ultra-violet rays into a building. `
R-Values of glass systems (2012):
Single-pane glass, clear: R-1
Single-pane glass with low-E: R-2
Two-layer insulated glass, clear: R-2
Two-layer insulated glass with low-E, argon filled: R-4
Two-layer with suspended film ‘SeriousGlass’: R-5-R-8
Triple-layer high-performance glass: R-9
Quad high performance glass: R-14
(for reference, a typical insulated wall has an R-value of R-13).
Innovation: The Wheel
Year: 3500 BC
One of the 6 classical ‘simple machines‘.
Evidence of the invention of the wheel appears in several cultures beginning in the late Neolithic period (appx. 3500 BC). An example of a simple machine, the wheel is one of the most ubiquitous technologies in the world. The first form of the wheel was carved out of large blocks of wood or stone. `