This folder contains correspondence concerning the technical and commercial development of Edison's battery-powered safety lamp and its attachment to headgear for a portable, hands-free light source. The correspondents include N. J. Richards, vice president and general manager of the Philadelphia & Reading Coal & Iron Co., one of the first companies to test Edison's safety lamps. Also included are interoffice communications by Edison associate H. H. Meno Kammerhoff regarding the shipment of lamps, patent applications, and other matters and a communication by employee Arthur Mudd relating to the "cost of experimental work on miniature cell for police and miners."

All of the documents have been selected.