This folder contains correspondence and other documents relating to Daniel Higham's patents on mechanical amplification devices and to Edison's interest in his work. The selected documents cover the period 1902-1904. Among the correspondents are Higham, Edison, and their respective patent attorneys, John B. Moran and the firm of Dyer, Edmonds, and Dyer. Included is an option agreement between Higham's High-Am-O-Phone Co. and the National Phonograph Co., along with numerous items pertaining to the execution and disposition of the agreement.

Approximately 50 percent of the documents have been selected. The items not selected include printed patents, letters of transmittal and acknowledgment, and documents that duplicate information in selected material.