Your Daily Facts about Lightbulbs
The first electric light was made in 1809 by Humphry Davy, an English scientist. He experimented with electricity and when he connected wires and a piece of carbon to a battery, the carbon glowed, producing light.
In 1875 Herman Sprengel invented the mercury vacuum pump making it possible to develop a practical electric light bulb by making a really good vacuum inside the bulb possible.
In 1878 Sir Joseph Wilson Swan, an English physicist, was the first person to invent a practical and longer-lasting electric light bulb (13.5 hours). Swan used a carbon fiber filament derived from cotton.
Incandescent lamps make light by using electricity to heat a thin strip of material (called a filament) until it gets hot enough to glow. Many inventors had tried to perfect incandescent lamps to “sub-divide” electric light or make it smaller and weaker than it was in the existing electric arc lamps, which were too bright to be used for small spaces such as the rooms of a house.
It Is clear that Tomas Alva Edison could not be credited with the invention of the electric light bulb (incandescent lamp). Nevertheless, his contribution to the perfection of this device is really impressing.
Until 1878 when Edison decided to throw the bulk of his attention and resources into the perfection of the light bulb the best source of lighting was gas. Unfortunately it was far from convenient. It was dirty, unhealthy, uncomfortable and dangerous. When gas burned it created soot everywhere. It degraded the air quality by emitting soot and depleting oxygen. During the summer it made the air even hotter and more uncomfortable. It caused explosions, fires and its care could not be trusted to children. But the major deficit of gas was that it could not serve as a source of power. The appliances we take for granted today – fans, refrigerators, electric irons and computers – could not be powered by gas, at least not in a convenient way.
On the other hand, light bulbs existing prior to Edison’s efforts burned for a short time – the best achievement was Swan’s, 13.5 hours, though a great breakthrough, not commercially yet.
Thomas Alva Edison, a prolific inventor, and his team (yes, he did not work alone!) experimented with thousands of different filaments to find just the right materials to glow well and be long-lasting. In 1879 Edison obtained an improved Sprengel vacuum pump, and it proved to be the catalyst for a breakthrough. Edison discovered that a carbon filament in an oxygen-free bulb glowed for 40 hours. Soon, by changing the shape of the filament to a horseshoe it burned for over 100 hours and later, by additional improvements, it lasted for 1500 hours.
In the period from 1878 to 1880 Edison and his associates worked on at least three thousand different theories to develop an efficient incandescent lamp.
He tested the carbonized filaments of every plant imaginable, including bay wood, boxwood, hickory, cedar, flax, and bamboo. He even contacted biologists who sent him plant fibers from places in the tropics. Edison acknowledged that the work was tedious and very demanding, especially on his workers helping with the experiments. He always recognized the importance of hard work and determination. “Before I got through,” he recalled, “I tested no fewer than 6,000 vegetable growths, and ransacked the world for the most suitable filament material.”
Edison decided to try a carbonized cotton thread filament. When voltage was applied to the completed bulb, it began to radiate a soft orange glow. Just about fifteen hours later, the filament finally burned out. Further experimentation produced filaments that could burn longer and longer with each test. By the end of 1880, he had produced a 16-watt bulb that could last for 1500 hours and he began to market his new invention.
Edison’s lamp would consist of a filament housed in a glass vacuum bulb. He had his own glass blowing shed where the fragile bulbs were carefully crafted for his experiments. Edison was trying to come up with a high resistance system that would require far less electrical power than was used for the arc lamps. This could eventually mean small electric lights suitable for home use.
Edison and his colleagues had invented a practical light bulb and by doing so they opened up the way for the establishment of the electrical power system.
Between the years 1878 and 1892 the electric light industry was growing in terms of installed lights but shrinking in terms of company competition as both Thomas Edison and George Westinghouse determined to control the industry and its advancement. They even formed the Board of Patent Control, a joint arrangement between General Electric and the Westinghouse Company to defend the patents of the two companies in litigation. This proved to be a wise decision as over 600 lawsuits for patent infringement were filed.
Edison didn’t just invent a light bulb, either. He put together what he knew about electricity with what he knew about gas lights and invented a whole system of electric lighting. This meant light bulbs, electricity generators, wires to get the electricity from the power station to the homes, fixtures (lamps, sockets, switches) for the light bulbs, and more. It was like a big jigsaw puzzle–and Edison made up the pieces as well as fitted them together. He did it his way.