Not Just Inventing

To provide electricity to towns, both residential and industrial, Edison began working on both - as well as a central power station - all at the same time.  His obvious first step would have been to subdivide the arc light, the proven source of light, but again Edison chose another path...

Edison's first step was to develop an electric light that would emit a small glow in an enclosed lamp.  This was "incandescent" light, not requiring a flame but used a filament to produce glowing white heat.  The "glow lamp" had been the focus for 50 previous years by this time, with no success.  Those in the years before had used filaments of metals or carbon in glass from which air was removed.  These glowed for only a few minutes and used a great deal of copper wire, making them quite expensive.  Thus the conclusion was that incandescent lighting was impossible, both in theory and practice.

Edison, of course, took a different approach and turned the problem around.  His filament used less current with higher voltage which resulted in using less copper wire.  Edison used 1/100 the amount of copper wire as previous experiments while producing a longer glow.  The whole idea suddenly became feasible.  By rethinking the problem, Edison had to just find the right burner.  He already knew the qualities needed so after trying all kinds of materials, he finally did a successful trial with a carbonized cotton filament in 1879.  This filament glowed for 40 hours!  Edison had improved the vacuum in his light bulb as well which extended the "glow time."

On November 1, 1879, Edison applied for a patent on a carbon filament lamp.  At the same time, he designed a parallel circuit whose 1000s of outlets could be independently turned off and on.  Along with that he designed an improved dynamo - making all of it possible.  Edison was not simply, "inventing" a new incandescent bulb anymore, he was organizing a new electric lighting system for communities,  That system which will change the world.

Next time...perfecting the system
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Today in Pioneer History: "On April 16, 1889, Charles Spencer Chaplin, Hollywood legend and my personal favorite, was born in London,  After a rough London childhood on the streets collecting pennies with his brother for entertainment.  His "tramp" made him a silent screen star.  What you may not know is that he and his partners, Mary Pickford and Douglas Fairbanks,  founded United Artists Movie Studio and Charlie wrote the song, "Smile."  Happy Birthday Charlie!