Courtesy Richard Moran, from "The Executioner's Current" The execution of William Kemmler, the first man to die in the electric chair, August 6, 1890

On Aug. 6, 1890, William Kemmler, a peddler from Buffalo, N.Y., who had murdered his mistress with an ax, became the first man to die in the electric chair. At 6:40 a.m., in the death chamber of Auburn state prison, Kemmler was administered two applications of electricity. The first, 1,300 volts, lasted for only 17 seconds and proved insufficient to kill him. The second charge was 2,000 volts. After four minutes, the smell of burning flesh filled the room as the condemned man caught fire. As soon as his charred body stopped smoldering, Kemmler was pronounced dead.

The Kemmler execution was not only a grisly milestone in the history of capital punishment; it was a notable episode in a public-relations war  the battle of the electrical currents  between Thomas Edison and his archrival, George Westinghouse. What was at stake was the public perception of alternating current (AC), the system promoted by Westinghouse in a fierce competition with Edison's direct current (DC). Almost from the time he introduced AC in 1886, four years after Edison unveiled DC, Westinghouse began to cut seriously into Edison's market share. So by 1888, Edison and his supporters had launched a campaign to convince the public of the dangers of AC, which operated at much higher voltages. Because AC dynamos manufactured by Westinghouse were the method chosen to supply the lethal current for the chair  despite the best efforts of Westinghouse to prevent it  the Kemmler execution became an opportunity for Edison to identify AC in the public mind as the "executioner's current." (Watch a video on the battle between AC and DC currents.)

The grotesque reality of the Kemmler execution notwithstanding, the electric chair was devised as a means of making capital punishment more acceptable to the American public. In the late 1880s, after several highly publicized hangings that were gruesomely bungled, support for the death penalty had begun to wane. Its defenders felt compelled to go in search of a more reliable and less painful method of execution. In 1887, Dr. Alfred Southwick, a member of a commission established by the New York State legislature to explore alternatives, including electrocution and lethal injection, contacted Edison by mail to seek his recommendations. At first the great man refused  he was, after all, an opponent of capital punishment. But when Southwick went to him again, Edison realized that this could be an opportunity. He suggested that the "best appliance" to kill "instantaneously" and with the "least amount of suffering" was an AC dynamo "manufactured principally...by George Westinghouse."

On June 4, 1888, New York State legalized death by electricity, though without specifying what kind of current should be used. The following day, Harold Brown, a self-taught New York City engineer, inserted himself into the crusade against AC. He wrote a letter to the New York Evening Post outlining the dangers of AC and accusing Westinghouse of placing his financial interests ahead of the public welfare. Brown then teamed up with Edison. At Edison's West Orange, N.J., laboratory, he conducted experiments demonstrating that less than 300 volts of AC would kill a dog that survived 1,000 volts of DC. Later, before a New York City audience of "electricians" and journalists, Brown electrocuted a 76-lb. (35-kg) dog named Dash. Afterward, he proclaimed that alternating current was suitable only for the "dog pound, the slaughterhouse, and the state prison."

One year later, the ax murderer Kemmler was sentenced to death by electrocution. Lawyers paid for by Westinghouse appealed the sentence to the New York State Supreme Court, claiming that electrocution was cruel and unusual punishment. Before an evidentiary hearing held to assess the issues raised by Kemmler's attorneys, Edison assured the court that death by alternating current was quick and painless. Predictably, Kemmler's motion was denied, as was a similar petition to the U.S. Supreme Court.

Despite the prominence of Brown's attacks on AC, the New York State superintendent of prisons hired Brown to design and install the first electric chair. With Brown building it, it would of course be an AC chair. As expected, Westinghouse refused to sell Brown his powerful AC generators. But with Edison working behind the scenes, Brown secured three through a secondhand dealer in Boston.

In the end, the controversies surrounding Kemmler's execution did not damage Westinghouse's business. Within a year, AC had captured 50% of the lighting market. In 1893, when Westinghouse Electric signed a contract to install AC generators at Niagara Falls, the battle of the electrical currents had been won  and not by Edison.

Richard Moran is the author of Executioner's Current: Thomas Edison, George Westinghouse and the Invention of the Electric Chair