Yablochkov candle

A Yablochkov candle consists of a sandwich of two electrodes, which are long carbon rods, approximately 6 by 12 millimetres in cross-section, separated by a block of inert and insulating material such as plaster of Paris or kaolin.

The arc then continues to burn, gradually consuming the carbon electrodes and the intervening plaster, which melts at the same pace.

In his trials to power more sets of candles with different light flux and in order to obtain different voltages, Yablochkov invented the first transformers.

When lit they produce buzzing noise, dangerous UV rays, carbon monoxide emissions and radio frequency interference.

[5] In 1875 Yablochkov left Russia and started his Paris business; by 1876 he was granted the French patent 112024 for his candles.

[6] The Yablochkov candles were first used commercially in 1877 in the Marengo hall of the department store Galeries du Louvre in Paris with an installation of 80 lamps.

[8] Werner von Siemens visited the 1878 Paris Exhibition and negotiated to become a distribution agent for the candles in Germany; in return he delivered dynamo machines to Yablochkov.