11. The first " Klieglight " was a powerful carbon arc light designed for the motion picture industry. 12. Carbon arc lamps consist of two carbon rod electrodes in open air, supplied by a current-limiting ballast.13. Some of his scientific endeavors after the war carried on with themes related to the carbon arcs . 14. In the 1920s, carbon arc lamps were sold as family health products, a substitute for natural sunlight. 15. The electrodes employed for twin-carbon arc welding are approximately of the same diameter as the workpiece thickness. 16. The English engineer William Duddell discovered how to make a resonant circuit using a carbon arc lamp. 17. It retains early carbon arc projectors. 18. The invention of the electric arc furnace probably began when Humphry Davy discovered the carbon arc in 1800. 19. In 1865, John Tyndall described radiation from electrically heated filaments and from carbon arcs as visible and invisible. 20. The company's product range included dynamos, lifts, carbon arc lamps, electric traction motors for trams and drilling equipment.
