In November 1885 electrical engineer William Stanley, Jr., a sometime Great Barrington resident working for George Westinghouse, began installing a demonstration transformer based alternating current lighting system. Stanley felt AC was an improvement over the direct current system being used by Thomas Edison, and Stanley was trying to get Westinghouse to adopt it. Stanley had developed a series transformer he thought would make AC practical. He built his components at the "Old Rubber Factory" south of Cottage Street and installed a Westinghouse steam engine powering a 500 volt Siemens generator. Stringing the power lines from tree to tree down the street, in March 1886 Stanley powered the system up and was able to expand it to the point where it could light 23 businesses along Main Street with very little power loss over . The system's 500 AC volt current was stepped down to 100 volts using the new Stanley transformer to power incandescent lamps at each location. This was the world's first practical demonstration of a transformer/alternating current system and the basis of the AC systems Westinghouse would begin installing later that year.