This file contains a copy, prepared by electrical engineer William S. Andrews, of Edison's instructions for three-wire central stations. The instructions, which deal mainly with dynamo sparking, were written a few days after the opening of the first three-wire station in Sunbury, Pennsylvania, in July 1883. An accompanying note by Andrews indicates that the original document was donated to the American Institute of Electrical Engineers in April 1907.

Courtesy of the Henry Ford Museum and Greenfield Village Research Center.