Philadelphia, Feb. [blank], 1795 Sir, Having from early age been concerned in working mines, and smelting and refining ores in Europe, and also several years engaged in the same line in the United States, I wish to become useful in promoting the opening of mines in this country - Henfrey, Benjamin (Printed by John Snowden and William M'Corkle, 1795)
Ascribed to the press of John Snowden and William M'Corkle by Evans. - Circular letter advertising a course of lectures on mineralogy; includes a syllabus. - Evans, 28822. - Rink, E. Technical Americana, 3345. - Signed: Benjamin Henfrey. From the Gap-Copper-Mines, Lancaster County