"The most important of my discoveries have been suggested to me by my failures."
Sir Humphrey Davy
The name of Sir Humphry Davy (1778-1829) will forever be associated with the famous safety lamp that he developed for miners, but his demonstration of the arc lamp in many ways was more significant.
Considered one of the greatest British scientists, Davy became renowned for his mesmerizing public lectures, including his demonstration of the effects of laughing gas. In 1801 the twenty-two-year-old Davy was appointed as the director of the laboratory at the new Royal Institution in London, where he began his work in electrochemistry.
It was here that he first discovered the principles behind what would eventually become the arc lamp. He used two sticks of carbon in the form of charcoal and connected each of them by wire to opposite terminals of a battery. When he held the two carbon "electrodes" a few inches apart, an electric arc jumped between them and completed the circuit.
The side effect was that, as the arc bridged between them, the tips of the carbon electrodes were heated to incandescence and glowed with a light that can only be described as dazzling. But it did not last long. In Davy's experiments, the spark connecting the electrodes formed a curved shape, due to the movement of air currents, and so he named his creation the "arch lamp." Eventually, however, it became known as the arc lamp.
Although spectacular, in some respects Davy's discovery was premature. The battery itself was still new to science, with the very first one having been demonstrated only a few years previously by its inventor, Alessandro Volta. Davy had to use 2,000 of them to power his lamp. Because of this lack of commonly available electricity, it was not until the 1870s that the arc lamp was used as lighting.
