Breastwheel

Breastwheel Breast"wheel` (br[e^]st" hw[=e]l`), n. A water wheel, on which the stream of water strikes neither so high as in the overshot wheel, nor so low as in the undershot, but generally at about half the height of the wheel, being kept in contact with it by the breasting. The water acts on the float boards partly by impulse, partly by its weight. [1913 Webster]