ABSTRACT
FROM THE EARLIEST colonial days untilwell after the Civil War, American iron-workers, sawyers, fullers, and mill operators relied on waterpower to drive bellows, saws, fulling mills, machine tools, cards, mules, and looms. During the seventeenth and eighteenth centuries most towns grew along the fall line of the Eastern seaboard, where the small rivers and streams dropped a few feet in elevation. Abrupt waterfalls were preferable to a series of rapids. A fall of i o-15 feet was sufficient to power the overshot and breast waterwheels of the period, and the quantity of water needed to operate a mill was not large. In numerous locations the millwright was satisfied to install a wooden headrace or to dig a shallow ditch from the pond upstream of a waterfall to the mill's wheelpit. At other sites millwrights built small dams to ensure a supply of water during dry periods. Such dams were small affairs of wooden cribs, frames, or even branches and tree trunks, seldom exceeding 5 feet in height (figs, i, 2, 3, 4, 5-1 If a freshet breached or carried away such a dam, as often occurred, repair or replacement was fairly simple.
