Electric Arcs - History

History

The phenomenon was first described in 1802, as a "special fluid with electrical properties", by Vasily V. Petrov, a Russian scientist experimenting with a copper-zinc battery consisting of 4200 discs. Sir Humphry Davy first demonstrated the arc early in the nineteenth century by transmitting an electric current through two touching carbon rods and then pulling them a short distance apart. In 1801, at a lecture before the Royal Society, he produced a "feeble" arc, not readily distinguished from a sustained spark, between charcoal points. The Society subscribed for a more powerful battery of 1000 plates and in 1808 he demonstrated the large-scale arc. He is credited with naming the arc. He called it an arc because it assumes the shape of an upward bow when the distance between the electrodes is not small. This is due to the buoyant force on the hot gas.