These documents include dated items from February 1882-October 1884 and undated material, possibly from 1882-1883. They consist primarily of correspondence from Edison to Charles L. Clarke, chief engineer of the Edison Electric Light Co. of New York. Most of the letters concern the construction and equipping of the Pearl Street station and other central stations, such as the one in Brockton, Massachusetts. Some items relate to the design of dynamos and motors and organizational changes at the company. Individuals mentioned in the documents include electrical engineer Hermann Claudius and electrical equipment manufacturer Sigmund Bergmann. A few of the undated letters were subsequently dated by Clarke.