This is the story of the incandescent lamp, and the man who put the hairpin in the bottle. In 1802, Sir Humphrey Davey of Penzance in England made a significant discovery. He connected strips of carbon and various metals to an electric battery, and found them to be heated white hot to incandescence, thereby producing a considerable degree of bright light. However, the light didn't burn for very long, as the materials were burned to dust quite quickly. He needed to find a solution...