Clay Furnace. First successful use of raw bituminous coal in place of charcoal, 1846; and of unmixed Lake Superior iron ore in 1856. Built 1845 by Vincent & Himrod; named for Henry Clay. Abandoned in 1861. The site is 2 miles away. N side of US 62 at Clay Furnace Rd., Charleston, PA by Pennsylvania Historical and Museum Commission Colour: blue Wikimedia: Flickr: Google Streetview OpenStreetMap