This folder contains correspondence relating to the business of the Lamp Manufacturing Department of the Edison General Electric Co., formerly the Edison Lamp Co. Many of the letters are by Francis R. Upton, general manager, and pertain to the testing and improvement of lamps. Also included are letters by Edison's inspector, C. A. Brown, about production problems at the lamp factory.

Approximately 60 percent of the documents have been selected. The following categories of documents have not been selected: routine correspondence regarding accounts, equipment, and orders; letters of transmittal and acknowledgement; duplicate copies of selected material.

Courtesy of Thomas Edison National Historical Park.