LONG ISLAND, a long narrow island off the E. coast of the United States of N. America, forming part of New York state, and separated from the mainland at its western extremity by two channels, called the Narrows and the East River, the former 1\frac{1}{2} mile, the latter \frac{2}{3} of a mile in width. It stretches from W.S.W. to E.N.E., between N. Lat. 40. 33. and 41. 6., and W. Long. 71. 50. and 74. 4., being 115 miles long, by from 12 to 20 miles broad, and containing an area of about 1448 square miles. A low range of hills extends from one extremity of the island to the other, exhibiting on the northern slope an irregular and broken surface, while on the S. the ridge declines more gently to the Atlantic. There are no large streams, and the want of water-power is much felt in the island. The soil is of a light sandy character, generally sterile on the southern coast, but productive at the western extremity, in King's and Queen's County. The coasts are much indented, forming numerous large lagoons on the southern coast, and an extensive inlet at the eastern extremity, which almost severs the island in two. A railroad, one of the first constructed in the state, and originally intended to accelerate the traffic between New York and Boston, traverses it from W. to E. Communication is kept up with the mainland by means of steam ferries at Brooklyn, Fort Hamilton, &c. The island is divided into the three counties of King's, Queen's, and Suffolk. Pop. (1860) 212,637, (1854) about 260,000. (See NEW YORK.)