Thomas Alva Edison is the most prolific inventor in history – a remarkable man whose refinement of the light bulb ushered in the age of electricity.

Thomas Alva Edison is the most prolific inventor in history – a remarkable man whose refinement of the light bulb ushered in the age of electricity.

Edison (1847–1931), a shrewd American businessman as well as an inventor, ended up with more than 1,000 patents to his name.

Most of his inventions were developed under his direction by a team at the world’s first research and development facility, which he set up at Menlo Park, New Jersey, USA.

The Menlo Park complex was made possible by income generated by one of Edison’s earliest successes – the quadruplex telegraph, a device that allowed four messages to be sent simultaneously along a single cable.

His other early hit was the stock ticker, which printed out share prices direct from the stock exchange, via telegraph.

Among his most famous inventions was the phonograph, the first sound recording device, comprising a cylinder wrapped in tinfoil into which a stylus would cut grooves.

It caused disbelief when he first showed it off. One scientist declared it a ventriloquist’s trick.

Other Edison triumphs included the kinetoscope, a stand-alone device for watching short films in amusement arcades, and an improved microphone for early telephones.

Some of his inventions were not entirely new. In many cases, he and his team simply made an existing idea more practical and commercially viable.

The light bulb is a good example. It had been known for decades that electric current can heat metal to a temperature high enough to make it glow – a phenomenon called incandescence.

Within months of the invention of the battery in 1800, scientists had seen this glow as current passed through very thin strips of metal.

They saw the potential of electric lighting, but the hot metal reacted with air and soon burned through.

For decades, inventors tried to find a way around this problem.

Putting the metal in a sealed glass ‘bulb’ and removing the air seemed to help – but hot metal evaporates in a vacuum, so this did not work for long either.

Using thin strips of bamboo or paper coated with carbon was better, and cheaper.

English physicist and chemist Joseph Swan (1828–1914) made a successful light bulb using carbon coated paper in the 1860s, but vacuum pumps at the time were not strong enough to remove all the air, so the carbon would sometimes catch fire.

He improved his design in the 1870s, with a ‘carbonised’ cotton filament and a better vacuum pump, and took out a patent in Britain in 1878 – a year before Edison did so in the USA.

Edison’s team improved the electric light. In 1879, their bulbs typically lasted for 1,800 hours.

Until then, no one had made one lasting more than 15 hours.

Edison’s were also cheap, to encourage people to buy into the other vital ingredient of electric lighting, electric power.

Edison formed the Edison Electric Illuminating Company, which opened the world’s second public power station at Pearl Street, New York, in 1882. (The first was in Godalming, Surrey.)

Electrification took decades to complete.

But eventually electric lighting took over from gas, which had been in widespread use since the early 19th century.

In the 1850s, there were 1,000 gasworks in Britain alone, the gas produced by heating coal.

In the 1930s, natural gas began to replace coal gas.

Natural gas remains a popular fuel for cooking and heating today – and for generating electricity, in gas-fired power stations.