The Eaton (Hopewell) furnace near Youngstown, Ohio (USA) represents the earliest American blast furnace found to have used charcoal and raw coal as a combinatory fuel in the production of iron. Built in 1802, it was the first blast furnace west of the Allegheny mountains. Several specimens of pig iron taken from the various horizontal and stratigraphic areas of the site were submitted to photomicrographic examination. Analysis indicates that the eaton ironworkers knew their business. Despite a cold furnace, they produced a strikingly clean direct metal equal essentially to modern iron. Indications are that earlier statements regarding the poor quality of limestone used as a flux may have been precipitous; the fact being that a self-fluxing ore may well have been utilized. Photomicrographs, references. -- ICCROM