Instead of decorating a Christmas tree with candles, Edward H. Johnson, inventor and vice president of Thomas Edison’s booming electric company, strung 80 red, white and blue light bulbs on his scrawny evergreen. The whole thing rotated six times per minute on an electric crank.
“I need not tell you that the scintillating evergreen was a pretty sight — one can hardly imagine anything prettier,” wrote a reporter for the Detroit Post and Tribune.
More than a century later, those 80 bulbs have multiplied into hundreds of millions of tiny electric lights — perhaps billions — decorating American homes and roughly 40 million live trees each year.
From those first simple strings of bulbs to computer-controlled LED light displays, we retrace the curious evolution of the holiday light bulb.
Arc Lights
Before the advent of the modern incandescent light bulb, chemist Humphry Davy tinkered with high-voltage arc lights. The devices allowed electricity to jump between two carbon rods, emitting a super-bright point of light.
The design wasn’t long-lasting or safe, however, pushing inventors to create self-contained incandescent lights.
Swan and Edison
The first incandescent lights came out of Sir Joseph Wilson Swan’s workshop as early as 1850. Swan filed a patent for the design in 1861, but the bulb’s carbon filaments burned out quickly in the presence of oxygen.
Thomas Edison was working on his own version and eventually wooed Swan into his company, effectively gaining rights to Swan’s light-bulb patents. Edison knew the secret to success was a better carbon filament (tungsten versions came years later), so his shop tested thousands of plant fibers looking for the best material.
Cotton fibers, which could stay lit for more than 1,500 hours, were found to be the best natural filament in 1880. Edison’s company continued to work on supporting technologies to make the device commonplace, including the parallel circuit, more durable glass bulbs, better dynamos, reliable voltage supplies, fuses, insulation, sockets and even light switches.
Read more at Wired
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