LL. D Cogswell Joseph Green, an American scholar, born at Ipswich, Mass., Sept. 27,1786, died in Cambridge, Mass., Nov. 26,1871. After graduating at Harvard college in 1806, he made a voyage to India as supercargo of a vessel, and on his return studied law with Fisher Ames in Dedham. He commenced the practice of law at Belfast, Maine, where he married a daughter of Gov. Gilman of New Hampshire. Her death, and a distaste for the profession, led him to abandon it, and to accept in 1814 a position as tutor at Cambridge. In 1816 he visited Europe, and joined his friends Edward Everett and George Ticknor in studies at Gottingen and other German universities, and in travelling on the continent. He remained abroad about four years, giving special attention to the principles of instruction and education, and already entertained the idea of forming a great public library in the United States. Returning home in 1820, he was appointed professor of mineralogy and geology and librarian in Harvard college. In 1823 he united with George Bancroft in founding the Round Hill school at Northampton, Mass. The plan of this institution had been suggested by observation of the best English and German preparatory schools, and during the five years that Dr. Cogswell was associate head of it, and for about the same period during which he conducted it alone, it attracted students from every part of the country, and exerted an important influence in advancing the standard of American education.

After leaving Northampton he had charge of a similar institution in Raleigh, N. C.; but prior to 1839 he settled in New York city, where he became editor of the "New York Review." Being introduced by Fitz-Greene Halleck to John Jacob Astor, he soon became interested and engaged in the great work of his later years. During the closing years of Mr. Astor's life Dr. Cogswell was in daily intercourse with him, living, at his request, in his house as his friend and companion, and arranging the plans and selecting the titles of the books for the great library which it was Mr. Astor's purpose to endow. It was the unnoticed preparatory labors of many years which gave to the Astor library, so soon after the realization of its endowment, its complete and orderly development. Dr. Cogswell was appointed by Mr. Astor one of the trustees of the fund, and designated by the trustees as superintendent of the library before its opening. He made three visits to Europe, examining the principal libraries and book marts of the old world, and collecting the books for the Astor library. The character of the collection demonstrates his appreciation of the value of all branches of knowledge, and his liberal sympathy with every intellectual pursuit.

He presented to the Astor library his own bibliographical collection, which was one of the largest and most valuable in this country. He had previously united with Mr. Andrew Ritchie in purchasing in Germany, and presenting to Harvard college, a cabinet of about 5,000 minerals; and had made to the botanic garden at Cambridge a donation of nearly 4,000 very choice specimens of dried plants of central Europe, which, with the assistance of Mr. Seringe of Bern, he had collected in Switzerland. During Dr. Cogswell'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 history, comparative value, and significance of the books he had collected. He continued to perform the active duties of superintendent with singular industry and fidelity, until the pressure of advancing years induced him to retire in 1860. Two years later, having changed his residence to Cambridge, Mass., he resigned the office of trustee.

After that time it was his habit to make annual visits of several weeks to his friends in New York. While his physical strength gradually failed, his intellectual powers remained unimpaired to the advanced age of 85, and his sparkling conversation was as interesting as in earlier years. His remains were interred in his native place, where a handsome monument is to be erected by his Round Hill pupils, to testify their affection for their old friend and instructor. He bequeathed one fourth of his moderate fortune to the Manning school of Ipswich, Mass.