CHARLES RIVER, a stream rising in Worcester co., Mass., and flowing through Norfolk and Middlesex counties into Boston harbor. The towns on its banks are Hopkinton, Milford, Bellingham, Franklin, Medway, Medfield, Sherburne, Dover, Dedham, Needham, Natick, Newton, Waltham, Watertown, Brighton, and Cambridge. It affords numerous sites for mills and factories, and is navigable to Watertown, 7 m. W. of Boston. The lower part of its course is the favorite training place of the boat clubs of Harvard university. It is now (1873) proposed to draw from the upper part of this river an additional supply of water for Boston.