Jablochkoff candles and stand or lamp
One of the big drawbacks to development of street lighting by arc lamps was the need for elaborate regulating gear and the clumsiness and inefficiency of the D. C. generators of the time. There were advatnages to be gained from the use of alternating currentys, both from the generation and distribution point of view, but disadvantages in the control of the carbons. These were largely overcome by the 'Candles' invented in France by M. Jablochkoff and patented in Britain in 1876 (No. 3552). When he was representing M. Breguet at an electrical echibition in London in that year, he handed the two remnants of his earlier design of candle to a Science Museum representative. No remnant remains of the hollow cylindrical outer carbons but what can be seen is the inner carbon rod surrounded by a consumable ceramic insulating material. Later, the design became much less candle-like in form. Two carbon pencils were seperated by a magnesia insulator and the arc was started by the consumption of a carbon bridgin piece when the current was switched on.