Saturday, 26 December 2015 05:20

The Light Bulb: A Simple Invention That Changed The World

Written by Lorne VanSinclair for the Orillia Packet & Times

As we’ve seen, artificial light has changed dramatically over the past century and a half, and it is still changing. We read of people stockpiling standard incandescent light bulbs because of the impending government ban on what they see as energy-wasting devices. They want us to use more efficient, but more expensive, LED and compact fluorescent bulbs which have the advantage of lowering our energy bills but give a harsher light. Fluorescents especially come with their own shortcomings, toxic mercury vapour being just one of them. The debate over which is better rages on.

We might think it odd that a simple thing like a light bulb would stir up such controversy but in fact it has a tumultuous and controversial history; with enough intrigue and drama for several movies.

There is, believe it or not, an active collector market for vintage light bulbs, as there is for just about all early electrical devices. There is also a brisk consumer market for reproductions or antique-looking bulbs. So-called Edison bulbs can now be found in just about any hardware store and there are hundreds of other variations available in specialty shops or on line.

129 bulbs contentThe Edison bulb gets its name because common wisdom says Thomas Edison invented the light bulb about a hundred years ago. Like most common wisdom, it’s not really true.

At least twenty two other people had come up with some form of incandescent electric light bulb before Edison, the first being British inventor Humphry Davy in 1805, more than 70 years before Edison’s first patent. Davy used a filament made of platinum because of its high melting temperature. His bulb worked well but was too expensive for practical use and he abandoned the project. Many others in Britain, Europe and North America took up the search for the perfect filament that would be cheap to produce and last a long time.

Part of the problem was getting all the air out of the bulb, any oxygen would cause the hot filament to just burn up. By 1870 new vacuum pumps had been invented and soon it was getting to be a close race. In England Joseph Swan had been working on a bulb for decades and by 1879 he had several patents and a good working model which he demonstrated for the Newcastle Chemical Society but it still wasn’t commercially practical.

In 1874 Henry Woodward and Matthew Evans, working together in Toronto, obtained a Canadian patent for a nitrogen filled bulb that used carbon rods for a filament. They also obtained a U.S. patent but the two had difficulty raising enough capital to further develop and commercialize their invention. There was no Dragons’ Den back then so they ended up selling their patents to Thomas Edison in 1879.

That same year Edison, who had been working on improving Swan’s bulb, patented his own version using “carbonized thread” as a filament. He finally settled on a carbonized bamboo filament, giving him a bulb that would burn for 1200 hours.

Edison hadn’t invented the light bulb; he put together the first long-lasting bulb that could be mass produced. But he didn’t do it just to sell light bulbs; he had much bigger plans than that.

The electric bulb was much better and safer than a candle or kerosene lamp but it was no good without electricity. While all the PR was focused on the bulb, Edison had also developed a dynamo for the power source and a meter to measure how much electricity was used. He didn’t just supply a light, he supplied a lighting system suitable for homes, factories and public places and he wanted everyone to use it. The next step was to develop standards.

He chose to use 100 volts because it was powerful enough to give a good light but wouldn’t kill anyone who touched the wires. His dynamo produced 110 volts to make up for loss during transmission. He chose to use direct current – like you would get from a battery – instead of alternating current even though AC had the advantage of being much easier to transport over long distances. Under Edison’s system the power plant worked best if it was in-house or very close to the consumer. Transmitting over long distances required very expensive and inefficient equipment. However the newly invented electric motor only worked on direct current, giving it the advantage. That soon changed.

In 1887 a former Edison employee, Nikola Tesla, developed a very efficient motor that worked on AC current. Tesla’s patents, and Tesla himself, were picked up by George Westinghouse who wanted the same thing as Edison but believed strongly that AC was the way to go. That set the stage for the nasty and protracted War of Currents between Westinghouse and Edison’s General Electric Company.
It takes a special kind of tenacity to be a successful inventor; you must believe in yourself and your product even if nobody else does, you shut out all the nay-sayers and carry on. It’s a characteristic that will help bring great success but once it gets you there, it can work against you.

Despite the obvious superiority of AC current, Edison dedicated himself to destroying it. He lobbied State Legislatures and started a publicity campaign on the dangers of AC. He even staged public animal killings (stray cats and unwanted cattle) in order to demonstrate how lethal AC was. He secretly paid two of his technicians to work with the State of New York to develop the electric chair even though he was against capital punishment. He felt the chair would further tarnish ACs image.

General Electric’s Board of Directors eventually overruled Edison and started making AC generators in 1892 but the delay was costly. In 1893 Westinghouse was awarded the contract to build the giant Niagara Falls generating plant, General Electric was given the consolation prize of building the transmission lines to Buffalo using Tesla’s patents.

Tesla was also quite eccentric and has since become a folk hero among vintage electronics enthusiasts. ACs prime advantage comes from the rapidly expanding and contracting magnetic field it generates. That field can travel through space and induce a similar current in another wire. This is how radio works (with a much higher frequency than the power grid). Tesla believed he could broadcast electrical power without the use of transmission lines and he spent the rest of his life trying to prove it. Today this idea would be opposed because of legitimate concerns over the effect of massive magnetic fields but back then the big problem was the lack of a way to charge consumers for their electric power. Tesla thought electric power should be free, power companies didn’t.

Tesla also had great tenacity but he never achieved his big dream. Although he made a lot of money from his patents, he spent his final years alone and frustrated, living in various hotels. He died in 1943 at the New Yorker Hotel, one of the last buildings in the world still using DC current.

Today antique bulb collectors range from those seeking the very rare and esoteric bulbs from the early days when companies all over the world were coming up with their own versions, to the people at the local building centre filling their shopping carts with every incandescent bulb they can find. In between there are thousands of industrial bulbs, odd shapes and ornamental bulbs to collect and many are still relatively easy to find.

Don`t worry, the incandescent bulb hasn’t been banned, but soon manufacturers won’t be able to make the higher wattage ones. Changing technology means incandescent bulbs will gradually become a thing of the past so now is a good time to start your collection.