January 10 – Flash of Genius

Today’s Factismal: The flashlight was invented 115 years ago today.

“If all seems dark, grab a flashlight.” That bit of folk wisdom wouldn’t have made much sense to people living in 1898, as there were no flashlights. Instead, people used candles and lanterns filled with whale oil or kerosene to provide light. But those lights came at a cost: they frequently set fire to the thing you were trying to see (not to mention the person trying to do the seeing). But Edison’s patent for an inexpensive, reliable light bulb in 1879 and Gessner’s development of the dry cell battery in 1886 pointed the way to a safer portable light source.

By 1896, Columbia (soon to be known as “Eveready” and “Energizer”) began to manufacture dry cell batteries out of zinc, ammonium chloride, and carbon. These batteries were lighter than the wet cells (such as the one in your car) and less likely to spill toxic chemicals. However, they could deliver power only in short bursts before needing to “rest” in order to build up a charge. Despite this shortcoming, they proved to be exceedingly popular.

And a large part of that popularity came from David Misell’s bright idea to combine the light bulb with the dry cell battery in a portable package that could be easily carried in the hand. Though there had been other battery-run lights before, none of them had been portable, long-lasting, or popular. Misell’s was all three.

Though he called his invention an “electric hand torch”, the public soon started calling it a “flashlight” because it could only provide flashes of light. He sold the rights to Eveready, who began manufacturing them in mass and started a word-of-mouth campaign by donating several hundred flashlights to the New York City police department. Today, flashlights come in sizes ranging from small enough to sit on a key to large enough to light a house. But they all spring from Misell’s flash of genius back in 1899.

If you’d like to have your own flash of genius, why not join a Science Hack Day? Groups of folks get together to show each other nifty new experiments they’ve done and equipment they’ve made. To find one near you, flash on over to:

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