"History of the Expedition under the Command of Captains Lewis and Clark, to the sources of the Missouri, thence across the Rocky Mountains, and down the River Columbia to the Pacific Ocean. Performed during the Years 1804-5-6, by order of the Government of the United States. Prepared for the press by Paul Allen, Esquire." In conformity to the act of Congress of the United States, entitled "An act for the encouragement of learning, by securing the copies of maps, charts, and books, to the authors and proprietors of such copies during the time therein mentioned." And also to the act, entitled, "An act supplementary to an act, entitled, "An act for the encouragement of learning, by securing the copies of maps, charts, and books, to the authors and proprietors of such copies during the time therein mentioned," and extending the benefits thereof to the arts of designing, engraving, and etching historical and other prints." DAVID CALDWELL, Clerk of the District of Pennsylvania.