Return to Electrical Article List
The History of the Light Bulb - An Electric Dawn
Who invented the light bulb then? An easy enough question to answer you might think. After all, every American schoolboy (and girl) surely knows that the great American scientific genius and inventor, Thomas Alva Edison invented the light bulb in 1879. He of the near incredible 1300 inventions and patents. There's a difference there; invention and patent. He did hold the patent and he did invent his own light bulb, and did indeed make it into a commercially viable and successful working invention by extensive research and development on original ideas, but he did not invent the light bulb. Instead, he bought the patents from those who did.
Man-made electrical lighting itself began in circa 1810 when a chemist in England called Humphrey Davy (who also invented the miner's safety lamp, known as the Davy lamp) invented the arc light. This worked by connecting a battery (itself invented in 1800 by Italian physicist Count Alessandro Volta, with the word volts being a derivative of his name) to two wires, and attaching the other ends of the wires to a strip of charcoal. The charcoal (which is a form of carbon remember) became electrically charged and began to glow, with arcs of electricity in the air surrounding it.
Then in 1820 Warren De La Rue placed a coil made of platinum into an empty tube and allowed an electric current to pass through to form the first known proto-light bulb. This lit up well enough but the problem was that the chosen material for the coil, platinum was and still is extremely expensive to obtain, making the design a non-starter for commercialization.
Finding the filament
The ideas for filaments (in this case, very fine wires) producing light, was then worked on for years by numerous scientists around the globe. This modern word comes from the Latin 'filare' which means 'to spin'. The theory behind this change of tack in research was developed by James Prescott Joule, an English physicist who stated that if an electric current was passed through a resistant conductor, (the filament), this would itself glow hot with a good amount of the thermal energy produced turning to luminous, or light-giving, energy.
The prize would be great, but so were the problems. The electric lamp had to be first safe, cost-effective, and then practical; as small as possible in size allowing for easy transportation and installation, and it had to light up the surrounding area well, and not burn out after only a short time. This last problem was the main obstacle to significant progress. Many different materials that had a high melting point were used in trials and all in a variety of inert, vacuum, or partial vacuum chambers. This last point was because the oxygen in the air, while vital for life to exist, causes fires to burn at lower temperatures and at faster rates.
A Swan crosses the line first
The year of 1840 saw the English physicist and chemist Joseph Wilson Swan join the race to produce a workable electric light and twenty years later in 1860 he patented an incandescent lamp with a filament made from carbonized paper in a partial vacuum. This was the world's first electric light bulb.
But only being an experimental version there were limits to its' illumination (it was quite dim) and it also could only be used very close to the source of power. The vacuum maintenance was also causing some trouble, so Swan, successful but frustrated, turned to other science projects and only returned to improving his invention in 1875 when he switched the filament to one of compressed and carbonized fibrous cotton thread.
In 1878 he demonstrated his new version. This was a year earlier than Thomas Edison, who had independently chosen the same textile for the filament in his light bulb, after he and his assistants had exhaustively tested 6000 alternative plant fibers from every corner of the Earth, before settling on cotton as the best.
Edison takes charge, (with some help)
Swan's improved lamp lit well for thirteen and-a-half hours. Edison did beat this, his lasting for a little under fifteen hours.
Thomas Edison however was no ordinary inventor and due to his numerous past successes and fame, had a number of wealthy industrialists providing him with money to back his projects. So he bought Swan's patent from the company that then owned it (not from Joseph Wilson Swan himself) and the latter passed into the history books (or the better ones, anyway).
Edison now began to rapidly improve the working life span of the light bulb. His further experiments leading to better and better versions until by 1880, his bamboo fiber filament lamp was a 16 watt bulb that lasted for anywhere between 1200-1500 hours.
Though this again was not entirely down to him. A large reason for the long burning filaments was the complete lack of oxygen inside the glass bulb. An inventor called Herman Sprengel had produced a device called a mercury vacuum pump, which was better than anything Swan or Edison himself had yet come up with at evacuating the air from the lamp's chamber. This at last could allow for the first 'long life' light bulbs.
And the design for the bulb itself employed by Edison was not his alone, his had evolved out of a glass concept invented by two Canadians: Henry Woodward and Matthew Evans; but they had been unsuccessful in finding willing backers for their bulb, and having no financial muscle themselves, ended up like Swan, having their rights to patent bought by Thomas Edison, and also like Swan, are hardly known today whilst Edison is regularly hailed as the father of the light bulb.
One should not belittle Edison, mind. He behaved perfectly legally at all times and improved the originals immensely, allowing them to become widespread in use. And although he did not get there first, his original had also been slightly better than the competition.
In the next century 1903 saw Willis Whitnew invent a metal-coating for the carbon filament which avoided the inside of the bulb turning dark with sooty residue. In addition to this, 1906 saw tungsten (still in common use today) making its appearance as the General Electric Company patented a way of producing filaments from this excellent candidate metal. Indeed Edison himself had known tungsten would eventually prove to be the best choice for filaments in incandescent light bulbs, but in his day, the machinery needed to produce the wire in such a fine form was not available. Engineering had come on in leaps and bounds in the intervening years but tungsten filament production was still a costly pastime for business until 1910 when William David Coolidge of General Electric improved the process of manufacture to make the longest lasting tungsten filaments available to all.
So the wonder of light bulbs were soon seen in all parts of the world where electricity itself stood proud, and even in some places where it didn't yet (which must have been unbelievably maddening). Little electric friends that make life so much easier for everyone, and they continued to evolve and adapt to a number of choices of types for different purposes, looks and occasions.
Here are just some of the changes that occurred.
- In the twenties the first 'frosted' light bulbs emerged.
- Also in the twenties; adjustable power beam bulbs for car headlamps, and neon lighting.
- The thirties saw the invention of little one-time flashbulbs for photography, and the fluorescent lamp.
- The forties saw the first 'soft light' incandescent bulbs.
- The fifties had Quartz glass and later, the halogen light bulb.
- The sixties and the seventies brought better ellipsoid reflectors and mirrors for even brighter bulbs.
- The eighties had new low wattage metal halides.
- The nineties produced the amazing 60,000+ hour magnetic induction light bulb invented by the Dutch electrical company Philips. Also, the popularization of new environmentally friendly bulbs like the full spectrum light bulb.
So what next? Who knows, maybe LED (Light Emitting Diodes) will replace them eventually but electric light bulbs probably still have a few tricks up their sleeves yet. They've already come a long way and will continue to brighten our lives in all their glorious shapes, sizes and colors for a long time to come.
About The Author
Matt Jacks is a successful home based freelance copywriter, one of experience and diversity. His numerous articles offer moneysaving tips and valuable insight on typically confusing topics.