Memorandum from J.H. Walthall to B.G. Gildersleeve regarding a site visit to a brown iron ore mine near Madisonville, Monroe County, Tennessee; the deposit appears unique and more mining is needed to shed light on its origin and extent; contains four analyses, 1 p. Also includes correspondence from B. Gildersleeve to J. Knight containing the results of an analysis of a sample of iron ore, 1 p. and original chemical result sheets, 3 pp.