CAMBRIDGE, a city of Ohio, the county-seat of Guernsey co. It is on the Baltimore and Ohio and the Pennsylvania railroads. It is the center of an important mining region and is the shipping point for coal and oil. It has tin-plate mills, an earthenware plant, glove factories, and other industries; the division shops of the Pennsylvania railroad; a public library, hospital, and other public buildings. Pop. (1910) 11,327; (1920) 13,104.