Cotton mill heated in 1816 by a young Robert Mills

Robert Mills, the American born architect of two Washington Monuments - Baltimore in 1815 and DC in the 1830s - designed a soap stone and brick furnace for the large (100 feet by 40 feet, three story stone) cotton mill a mile down the Patapsco River from Ellicott's Mills.  It was run by Edward Gray, father-in-law of John Pendleton Kennedy.  More on "Patapsco" HERE