breastwheel

from The Century Dictionary.

• noun A water-wheel with radial floats or buckets, upon which the water is admitted at any point from about the plane of the axle to 45° or more above it.

from the GNU version of the Collaborative International Dictionary of English.

• noun 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.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun 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 float boards partly by impulse, partly by its weight.