At school we are taught that Thomas Edison invented the lightbulb in 1879 and thus changed the way we live. However is this the full story? Find out the truth behind the lightbulb by reading on;
The idea of using electricity to generate a light source can be traced back to almost the beginning of the 19th century. Indeed, in 1806 Sir Humphry Davy had demonstrated to the Royal Society that when current was passed through two carbon rods held close together but not touching, that a spark would jump across the gap and that this spark produced an intense, bright light. Unfortunately though, this crude arc lamp was largely impractical in everyday life. The light produced was too intense, the lamp quickly drained batteries and was cumbersome. Even with the advent of better power sources the practicality of the arc lamp was limited, although its great power led to it being installed in lighthouses and other places where an intensely bright light was needed. In 1871, Souter Lighthouse on the North East coast of England came into operation and was the first in the world to combine an arc lamp with an alternating current power source, thus becoming the most advanced and effective of its day.
However, other scientists, recognising that the arc lamp was impractical for more everyday use sought an alternative means of using electricity to generate light. The obvious thought was that when certain materials have an electric current past through them, they heat up and begin to glow. The problem with this method was finding a material that didn't either melt or burn easily. In order to prevent the filament from burning, the easy answer was to remove oxygen and of course the only way of doing this was to place the filament in a vacuum within a container. In 1841, Frederick De Moleyns did exactly that, encasing a filament within a bulb and pumping the air out. Thus the concept of the incandescent bulb was born. De Moleyns was quickly followed by J.W. Starr, an American who patented a carbon filament bulb in 1845. However neither of these devices was particularly successful as only a partial vacuum could be achieved and the bulbs quickly burnt out.
Incremental advances were being made however and in 1860, Joseph Swan, a chemist from Sunderland in the UK received patent for a partial vacuum, carbon paper filament incandescent bulb. However the device remained largely impractical like its early predecessors. 15 years later Swan had advanced his bulb to incorporate a better vacuum and a carbonized thread filament. This design had a lifespan of around 14 hours. Crucially Swan was granted patent for this design in 1878. It was this design that Thomas Edison took and developed further so that it late 1879 he had developed a bulb that would last 40 hours. This, although not the first incandescent lightbulb was the first truly practical device.
Given the closeness of the Swan and Edison developments in both time and design, Edison was keen to avoid any sort of litigation and thus the Ediswan company was formed in order to market and sell lightbulbs in Great Britain.
So did Edison invent the incandescent lightbulb? No. Did he contribute to its development as a practical device which become commonplace in almost every building? Most definitely. However, ultimately development of the lightbulb was perhaps more than anything a group development. From Davy's arc lamp, through De Moleyn's charcoal filament, through Swan's carbon filament, Edison's longer lasting filament design, through Latimer's methods of manufacturing filament to Coolidge's tungsten filament development in 1910, the evolution of the lightbulb can be shown to be a collaboration of some of the best minds of the time.