This folder contains correspondence and other documents relating to the business of the Edison Lamp Co. through July 1890, when it became a department of the Edison General Electric Co. Included are letters pertaining to the introduction of 20-candlepower lamps, the problems of defective lamps, and other technical matters. There are also cost sheets and production and payroll statistics. Most of the correspondence is by Francis R. Upton, general manager and treasurer, and by William H. Meadowcroft, secretary to Mr. Upton.

Approximately 50 percent of the documents have been selected. The following categories of documents have not been selected: routine business correspondence relating to advertising, financial, and shipping matters; letters of transmittal and acknowledgement; meeting announcements.

Related material can be found in D-90-34 (Edison General Electric Co. - Lamp Works).