This folder contains correspondence and other documents relating to the procurement and testing of batteries for Edison's phonoplex and phonograph. Included also are documents pertaining to William E. Hidden's search for chrome to be used in batteries.

Approximately 60 percent of the documents have been selected. The following categories of documents have not been selected: field reports by Hidden; routine correspondence regarding the ordering and shipment of batteries; printed circular from the Electrical Accumulator Co; directions for setting up a secondary battery.

Related documents can be found in D-89-32 (Edison Manufacturing Co.) and in D-89-68 (West Orange Laboratory - General).

Courtesy of Thomas Edison National Historical Park.