Rensselaer, an E. county of New York, bordering on Vermont and Massachusetts, bounded W. by the Hudson river, and drained by the Hoosick and Little Hoosick rivers, and Kinderhook creek; area, 690 sq. m.; pop. in 1870, 99,549. Two ranges of mountains, the Taghkanick and Petersburg, traverse it from N. to S.; they have an elevation of from 1,000 to 2,000 ft., with precipitous declivities, studded with numerous small lakes. The soil is generally hard and sterile, but much of it is under cultivation, yielding liberal crops. Several railroads pass through the county. The chief productions in 1870 were 5,527 bushels of wheat, 187,383 of rye, 211,968 of Indian corn, 717,845 of oats, 49,762 of buckwheat, 1,504,209 of potatoes. 108,214 tons of hay, 235,496 lbs. of wool, 1,271,128 of butter, 365,-416 of cheese, 43,286 of hops, 774,773 of flax, and 54,513 of maple sugar. There were 9,372 horses, 16,813 milch cows, 1,358 working oxen, 8,585 other cattle, 54,928 sheep, and 9,276 swine. The county contained 792 manufacturing establishments, employing 15,588 hands, and having an invested capital of $12,354,181, with annual products amounting to $28,550,-306. The principal manufactures are iron and iron ware of many kinds, agricultural implements, bells, cotton and woollen goods, brick, linen and paper collars, carriages and wagons, machinery, marble and stone work, flour, lumber, paper, and leather.

Capital, Troy.