- Sir Humphrey Davy - Electric light first produced chemically - Magneto-electric: Holmes, Alliance, De Meritens — Dynamo-electric: CHAPTER III.-LAMPS AND REGULATORS. General duties and requirements - Voltaic arc- - Incandescence. mann - - Carbons: Natural, cut out of graphite deposit—Artificially prepared — Metallized Conducting wires: Continuous and alternating-direction currents-Examples-Differences in practice-Question still open for Steam, gas, water, &c. - Extreme regularity requisite - Special engine, not doing other work- Rate of speed-Estimate, as generally stated, too low-Power absorbed by electric machine, and also gross power required Light produced varies with nature of current and with form of lamp --Continuous current: Gramme, Siemens-Alternating current: Alliance, Lontin, Jablochkoff-Actual illumination — Conditions of preference -Photometric measurements - Clear understanding required - Photo- meters of Bunsen, Rumford, and Wheatstone-Standard of comparison.. 59 South Foreland, Souter Point, Lizard, and Cape La Hève Lighthouses. Northern of France Ry., Powell, Lyons Ry., Western of France Ry., and Gaiety Wallace-Farmer, Liverpool Street Station, London. Economic result afforded by effective illuminating power in proportion to working cost — Comparison of different examples - Effect of sub- 74 Practical solution only effected for certain cases Solution of remainder of problem - Difficulties to be removed. Too much at present expected from electric light- Comparison of cost of production of electric light at retail price with that of gas at wholesale price, not a fair one - Sanitary aspect-Ultimate distribution of electric lighting-Tendency to a more |