This folder contains correspondence and other documents relating to Edison's search for an inexpensive supply of cobalt ore for possible use in his alkaline storage battery. Included is correspondence with the North American Lead Co., the Standard Consolidated Mines Co., and field workers whom Edison employed in his search.

Approximately 40 percent of the documents have been selected. Among the items not selected are letters from companies and individuals seeking to interest Edison in various propositions for mining or processing cobalt ores, along with routine progress reports from field workers.