1905

In this year, GEM (or General Electric Metallized) filaments, invented by Dr. Willis Rodney Whitney [see A48] of the General Electric Company, were introduced.  The filament is round but not thread like, has a dull gray appearance and could be found mounted in a hairpin fashion, two filaments in series, or as a single oval anchored loop of one filament in a straight-sided bulb.  Although GEM light bulbs were successfully marketed to the public, the lamps faced competition from the newer and more popular tungsten lamps [see A89].  Manufacturing of all GEM lamps ceased in 1918 during the First World War when the United States Fuel Administration asked that all incandescent lamp manufacturers abandon the production of many carbon lamps, including the GEM lamps.  This was an unprecedented energy conservation movement that probably saved one million tons of coal every year, a huge amount during that time.  GEM lamps were subsequently replaced by tungsten lamps.

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