COGSWELL, Joseph Green, bibliographer, was born in Ipswich, 3lass., 27 September, 1786; died in Cambridge, Massachusetts, 26 November, 1871. He was graduated at Harvard in 1806. After making a voyage to India as supercargo of the vessel in which he sailed, Dr. Cogswell practiced law for a few years in Belfast, Maine In 1812 he married Mary, the daughter of Governor John Taylor Gilman. She died in 1813. From 1813 till 1815 he was a tutor at Harvard. In 1816 he went to Europe, and, in company with George Ticknor, spent two years at the University of Gottingen, where they advanced together in the special culture that has associated their names with what is highest in American literature and bibliography. Two more years were passed in Europe, chiefly on the continent, in the principal capitals, and in the study of educational problems and bibliography. During part of this time Edward Everett was his companion. He was, with his friend Ticknor, the guest of Sir Walter Scott, at Abbotsford; and contributed to "Blackwood's Magazine" a paper on American literature which attracted much attention. Returning to the United States in 1820, he was appointed professor of geology and mineralogy, and College librarian at Harvard. In 1823, having resigned his chair in Harvard, he, in connection with George Bancroft, the historian, established the Round Hill school, at Northampton, Massachusetts. The plan of the institution was novel, and based on an examination of the best English and German sys-terns of education. After Mr. Bancroft's retire-merit in 1830, Dr. Cogswell continued the school for six years, when he assumed the charge of a similar institution in Raleigh, North Carolina Abandoning this field of labor, he accepted the editorship of the "New York Review," one of the ablest critical journals then existing in the country, which he conducted till its suspension in 1842. Becoming the friend and companion of John Jacob Astor, he, in conjunction with Washington Irving and Fitz-Greene Halleck, arranged with him the plan of the Astor library. With Halleck, Irving, and others, Cogswell was appointed a trustee of the fund for its creation. When Washington Irving was appointed minister to Spain, he was anxious that his friend Cogswell should accompany him as secretary of legation, and accordingly wrote to Washington, requesting his appointment. "He is," said Irving, "a gentleman with whom I am on terms of confidential intimacy, and I know no one who, by his various acquirements, his prompt sagacity, his knowledge of the world, his habits of business, and his obliging disposition, is so calculated to give me that counsel, aid, and companionship, so important in Madrid, where a stranger is more isolated than in any other capital of Europe." Cogswell received the appointment, and would probably have accepted it, but, Astor finding that he was likely to lose his invaluable services, made him superintendent of the embryo library. After the rich merchant's death, he went abroad to purchase books; and it may safely be said that no library in the land was founded with more discrimination and economy. The books purchased by him would sell to-day for ten times the amount that he expended, while many of them cannot now be bought at any price. He gave the Astor library his own valuable series of works relating to bibliography, as he had before united with a friend in presenting Harvard with a rare cabinet of minerals and numerous botanical specimens. During Dr. Cogs-well's active superintendency of the Astor library, he prepared a valuable alphabetical and analytical catalogue of its contents, which was published in eight large volumes, displaying his extraordinary knowledge of the comparative value and significance of the books he collected. He continued the duties of superintendent, which he had performed with singular industry and fidelity, until the pressure of advancing years induced him to retire. Two years later, having chosen a residence at Cambridge, he also resigned the office of trustee. In accepting his resignation, the board passed a resolution highly complimentary to his talents, great learning, and spotless character. All who enjoyed the privilege of Dr. Cogswell's acquaintance, and the thousands of seekers after information who remember the patience and urbanity with which he was ever ready to aid them in their researches, will most cordially unite in the richly merited tribute to his learning, amiability, and unsullied life. While his physical strength gradually failed, his intellectual powers remained unimpaired, and his sparkling table-talk was as interesting as in earlier years. He had, in his frequent visits to Europe, met many of the most distinguished men of the 19th century, including Goethe, Humboldt, B5ranger, Byron, Scott, Jeffrey, and the brilliant circle that thronged Gore House in Lady Blessington's pahny days. Dr. Cogswell left, of his moderate fortune, $4,000 to a school in his native place, where he was buried by the side of his mother's grave, and where a handsome monument has been erected by his Round Hill pupils, no one of whom ever left the school without carrying away with him a strong affection for the faithful friend and teacher. He received the degree of LL.D. from Trinity in 1842, and from Harvard in 1863. He was a frequent contributor to the magazines, including "Blackwood's," "The North American Review," "The Monthly Anthology," and "The New York Review." See "Memorial Volume," by Anna E. Ticknor (printed privately, Boston, 1874).