section_path: Menlo Park laboratory (1876–1886)/War of currents
section_name: War of currents
paragraph_text: War of currents
  
  As Edison expanded his direct current (DC) power delivery system, he received stiff competition from companies installing alternating current (AC) systems. From the early 1880s, AC arc lighting systems for streets and large spaces had been an expanding business in the US. With the development of transformers in Europe and by Westinghouse Electric in the US in 1885–1886, it became possible to transmit AC long distances over thinner and cheaper wires, and "step down" (reduce) the voltage at the destination for distribution to users. This allowed AC to be used in street lighting and in lighting for small business and domestic customers, the market Edison's patented low voltage DC incandescent lamp system was designed to supply. Edison's DC empire suffered from one of its chief drawbacks: it was suitable only for the high density of customers found in large cities. Edison's DC plants could not deliver electricity to customers more than one mile from the plant, and left a patchwork of unsupplied customers between plants. Small cities and rural areas could not afford an Edison style system, leaving a large part of the market without electrical service. AC companies expanded into this gap.
  
  Edison expressed views that AC was unworkable and the high voltages used were dangerous. As George Westinghouse installed his first AC systems in 1886, Thomas Edison struck out personally against his chief rival stating, " Just as certain as death, Westinghouse will kill a customer within six months after he puts in a system of any size. He has got a new thing and it will require a great deal of experimenting to get it working practically. " Many reasons have been suggested for Edison's anti-AC stance. One notion is that the inventor could not grasp the more abstract theories behind AC and was trying to avoid developing a system he did not understand. Edison also appeared to have been worried about the high voltage from misinstalled AC systems killing customers and hurting the sales of electric power systems in general. The primary reason was that Edison Electric based their design on low voltage DC, and switching a standard after they had installed over 100 systems was, in Edison's mind, out of the question. By the end of 1887, Edison Electric was losing market share to Westinghouse, who had built 68 AC-based power stations to Edison's 121 DC-based stations. To make matters worse for Edison, the Thomson-Houston Electric Company of Lynn, Massachusetts (another AC-based competitor) built 22 power stations.
  
  Parallel to expanding competition between Edison and the AC companies was rising public furor over a series of deaths in the spring of 1888 caused by pole mounted high voltage alternating current lines. This turned into a media frenzy against high voltage alternating current and the seemingly greedy and callous lighting companies that used it. Edison took advantage of the public perception of AC as dangerous, and joined with self-styled New York anti-AC crusader Harold P. Brown in a propaganda campaign, aiding Brown in the public electrocution of animals with AC, and supported legislation to control and severely limit AC installations and voltages (to the point of making it an ineffective power delivery system) in what was now being referred to as a " war of the currents ". The development of the electric chair was used in an attempt to portray AC as having a greater lethal potential than DC and smear Westinghouse, via Edison colluding with Brown and Westinghouse's chief AC rival, the Thomson-Houston Electric Company, to ensure the first electric chair was powered by a Westinghouse AC generator.
  
  Edison was becoming marginalized in his own company having lost majority control in the 1889 merger that formed Edison General Electric. In 1890 he told president Henry Villard he thought it was time to retire from the lighting business and moved on to an iron ore refining project that preoccupied his time. Edison's dogmatic anti-AC values were no longer controlling the company. By 1889 Edison's Electric's own subsidiaries were lobbying to add AC power transmission to their systems and in October 1890 Edison Machine Works began developing AC-based equipment. Cut-throat competition and patent battles were bleeding off cash in the competing companies and the idea of a merger was being put forward in financial circles. The War of Currents ended in 1892 when the financier J.P. Morgan engineered a merger of Edison General Electric with its main alternating current based rival, The Thomson-Houston Company, that put the board of Thomson-Houston in charge of the new company called General Electric. General Electric now controlled three-quarters of the US electrical business and would compete with Westinghouse for the AC market. Edison served as a figurehead on the company's board of directors for a few years before selling his shares.