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To show that someone has a “bright idea,” cartoonists often draw a light bulb over the person’s head. You’ve probably seen this many times. It’s not only a sign of instant wisdom. It’s also a tribute to the genius of Thomas Edison.
Edison didn’t “invent” electricity. And he didn’t create the first electric lighting. But he did find a way to put electric lighting into homes and offices on a large scale.
Once Edison got an idea, he didn’t care what it cost. Because of his success, he got the money he needed for his projects. A group of businessmen formed the Edison Electric Light Company. They gave Edison $30,000 to start work.
▲ Today, we take electric power for granted. But it didn’t happen overnight. Over the years, many scientists added to what we know about electricity. They showed that it flows from object to object. They showed that some objects conduct it better than others. They also showed that lightning is a form of electricity. Alessandro Volta (shown seated in the picture above) was an Italian inventor. In 1800, he made an electric battery. Hans Christian Oersted, who was from Denmark, soon took things a step further. He showed that wires carrying electric currents acted like magnets. Michael Faraday was an English inventor. In 1831, he showed that magnetism could produce electricity. Faraday’s work formed the basis of Edison’s work with electricity.
By the early 1870s, some outdoor areas were using a kind of electric lighting. It was called arc lighting. But it had two problems. First, it was too bright to use indoors. Second, the current flowed in one direct line. If one light went out, all the other lights went out, too.
▲ To find the right filament, Edison did what he usually did. He used trial and error. For a while, he worked with only platinum, without success. The metal also cost a lot. So Edison went back to his old standby, carbon. There was plenty of carbon at the Menlo Park lab. It was used to make telephone transmitters. Edison’s assistant Charles Batchelor tried making carbon by lightly burning many substances. He tried celluloid, cedar, coconut hair, fishing line, and cotton soaked in boiling tar. Then he tried cotton thread. On October 22, 1879, Edison and his assistants took turns watching a bulb that used this thread. It burned for about 13½ hours. The team had succeeded! They had invented a working electric light bulb.
“I owe my success to the fact that I never had a clock in my workroom.”
—Edison
The burnt cotton thread worked. But Edison wasn’t sure it was the best material. So he kept trying other things. In the summer of 1880, he settled on lightly burnt bamboo fiber for his filament.
▲ Once Edison had settled on a filament, his backers were happy. Their money had been well spent. Now they wanted their rewards. For over two years, Edison oversaw the building of an electric power station. It was located on Pearl Street, near New York City’s big business district. On September 4, 1882, a switch was pulled. Then the first 85 customers of the Edison Electric Illuminating Co. of New York lit their new electric lamps.
Check It Out!
What material is used in incandescent light bulbs today?
Today, filaments are made of tungsten, a strong metal. They were developed around 1910.
