alexander graham bell alternating current arlington national cemetery automobile charles algernon parsons chicago direct current electric chair electric motor electric power electricity electro-pneumatic action elihu thomson engineer england entrepreneur france franklin institute franklin leonard pope gas engine general electric george westinghouse bridge heat pump hydropower ieee edison medal incandescent light bulb induction motor lewis howard latimer list of inventors london lucien gaulard manhattan multiplexing nernst lamp niagara falls nikola tesla ohio state university patent peter cooper hewitt phonograph pittsburgh polyphase railway signal reginald fessenden rotary engine rotating magnetic field schenley park serbia shock absorber steam engine steam turbine telegraphy thermodynamics thomas edison timeline of transportation technology transformer turbine united states volt war of currents westinghouse park william kemmler william le roy emmet