1Thomas Jefferson to Nathaniel Ellicott, 24 March 1811 (Jefferson Papers)
...your advice to the small scale to which I shall confine myself. there will not be offered more than 40. or 50. tons a year for grinding. half that quantity has already destroyed an excellent pair of mill stones for me, so that I am tired of that mode. I propose to place an overshot wheel for this machine, below the water wheel (an overshot) of my mill, to recieve it’s water by a prolongation...