breastwheel

plural breastwheels

1. A water wheel where 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 floatboards partly by impulse, partly by its weight.

   1 more example

   The saw-mill was recently erected by Mr. Leavens, who is a practical millwright. It is of the kind commonly used in the United States, and the manner of applying the water is rather different from which we generally see in England. There is a fall of water of about ten feet, which, instead of being applied to an overshot or breast-wheel, is allowed to rush out of a longitudinal aperture at the bottom, against the narrow floats of a wheel only twenty inches in diameter, which thus revolves with great velocity, and communicates motion by means of a crank and connecting-rod directly to the saw.

   1889, Alfred R. Wallace, A narrative of travels on the Amazon and Rio Negro, Chapter 2