Edison Built the Electric Chair to Stop Alternating Current. A Transformer Sent It 26 Miles to Buffalo.

Edison's direct current needed a power station every mile and a fortune in copper wire. Westinghouse's alternating current could be stepped up to high voltage, sent on thin wire, and stepped down at the door. Edison electrocuted dogs and built the electric chair to make AC seem lethal. The economics of copper wire settled it.

On September 4, 1882, Thomas Edison opened the Pearl Street Station in lower Manhattan, the first commercial electric power plant in the United States. It served one square mile of the financial district, ran at 110 volts of direct current, and required 100,000 feet of underground copper wiring, the most expensive part of the entire $300,000 project. The copper was the problem. Direct current could not be transformed to a higher voltage, so it stayed at 110 volts from generator to lightbulb, which meant the current was high, which meant the wire had to be thick, which meant a station could only reach customers within half a mile before losses made it uneconomic. Every neighborhood needed its own powerhouse.

George Westinghouse, the railroad air-brake inventor, saw the opening. In 1885 he read about European transformers that could step alternating current up to high voltage for transmission and back down for use. High voltage means low current means thin cheap wire means one station can serve a seven-mile circuit instead of a single street. He formed the Westinghouse Electric Company in 1886, licensed Nikola Tesla's polyphase AC motor in 1888 so alternating current could drive factory machinery and not just lamps, and by the end of 1887 had 68 AC stations to Edison's 121 DC stations, with Thomson-Houston adding 22 more.

Edison's response was to make alternating current seem deadly. In November 1889 he published "The Dangers of Electric Lighting" in the North American Review, calling AC "as unnecessary as they are dangerous" and admitting that his own company had bought AC patents over his protest, a fact he recorded "upon its minute-book." His ally Harold Brown electrocuted dozens of dogs, calves, and horses at Edison's West Orange laboratory, then proclaimed AC suitable only for "the dog pound, the slaughterhouse, and the state prison." When New York State adopted the electric chair, Edison's people acquired Westinghouse generators through a Boston dealer to power it. On August 6, 1890, William Kemmler became the first man executed by electricity. The first jolt of 1,300 volts failed. The second, at 2,000 volts, set him on fire. The technique was dubbed "Westinghousing".

Within a year, AC had captured 50 percent of the lighting market. In 1892, J.P. Morgan merged Edison General Electric with Thomson-Houston, dropped Edison's name, and the new General Electric immediately started selling AC. Two demonstrations made the verdict official. At the 1893 World's Columbian Exposition in Chicago, Westinghouse underbid GE, $399,000 to $554,000, because AC needed far less copper wire. He lit 100,000 bulbs, and 27 million visitors walked through the result. Then at Niagara Falls, Westinghouse generators sent power 26 miles to Buffalo at 11,000 volts. Even the Edison systems converted to alternating current.

The binding constraint was the price of copper. Edison's system was a geometry problem: low voltage meant thick wire meant short reach meant a station on every block. The transformer dissolved the constraint. Edison could electrocute dogs, lobby legislatures, and build the electric chair, but he could not make copper cheaper. FUD delays; economics decides. The incumbent who fights a structurally superior technology with propaganda loses the market and, in Edison's case, loses his own company. The one who adopts it the day the merger closes keeps selling.