Blackwell's Island is a narrow strip of land in the East river, extending from Fifty-first to Eighty-eighth streets, about a mile and a half in length, and contains one hundred and twenty acres. It was early patented to Governor Van Twiller, and was subsequently owned by the Blackwell family, from whom it derives its name, for more than a hundred years. The ancestral residence, a cozy wood cottage over a hundred years old, situated near the centre of the island, is still in fine repair, and likely to long survive the present generation. This island was purchased by the city July 19, 1828, for the sum of $30,000, but the authorities were compelled in 1843 to expend $20,000 more to perfect the title. The little steamers owned by the Commissioners, making several trips per day in the interest of mercy and justice, are the only vessels allowed to land at her piers without special permit. The labor of docking, building sea wall, and the admirable grading by which the island is made to slope gradually on either side to the water brink, has all been performed by inmates of the Penitentiary and Workhouse. The island is now valued at $600,000 exclusive of buildings.