BALTIMORE, a northern county of Maryland, bounded N. by Pennsylvania and S. by the Patapsco; area, 718 sq. m.; pop. in 1871, 330,741, of whom 47,921 were colored. The larger portion of the surface is undulating, with wooded ridges enclosing fertile valleys, and with bold hills often rising to a height of 800 ft. above tide water. The principal varieties of rock are granite, gneiss, hornblende, limestone, and a ledge of primitive rock running through the southeastern portion of the county. On the Great and Little Gunpowder, the Patapsco, Gwynn's and Jones's falls are large cotton, woollen, and carpet factories, furnaces, founderies, paper and flour mills. Copper and iron are found in considerable quantities, and in this and Harford counties are the most productive mines of chrome in the United States. In the neighborhood of Texas and Cockeysville are extensive quarries of marble, from which came the large monoliths of the capital at Washington, and the fine-grained alum marble used in building the patent office. The soil is moderately rich. The chief productions in 1870 were 264,568 bushels of wheat, 31,182 of rye, 856,754 of Indian corn, 375,063 of oats, 201,754 of potatoes, 35,791 tons of hay, and 544,888 lbs. of butter. The value of the principal manufactures in 1866 was: flour and meal, $2,425,887; cotton, $2,113,414; machinery, $1,100,000; woollens, $435,250; iron, $612,594; paper, $297,400; hides and leather, $294,981; liquors, $162,277. The county seat was transferred in 1854 from Baltimore to Towsontown.