 In 1885 Westinghouse imported a number of Gaulard–Gibbs transformers and a Siemens AC generator, to begin experimenting with AC networks in Pittsburgh.Stanley, assisted by engineers Albert Schmid and Oliver B. Shallenberger, developed the Gaulard–Gibbs transformer design into the first practical transformer.In 1886, with Westinghouse's backing, Stanley installed the first multiple-voltage AC power system in Great Barrington, Massachusetts, a demonstration lighting system driven by a hydroelectric generator that produced 500 volts AC stepped down to 100 volts to light incandescent bulbs in homes and businesses.