an architect, they signed a petition to President Madison for his admission to the corps of Topographical Engineers, which was then to be organized, and he was at once transferred to the United States Army. A short time after, General Bernard, whom Mr. Crawford, the American Minister at Paris, had engaged to be the chief of the Topographical Engineers, arrived in Washington, and assuming his office proceeded to the necessary preparations for that survey of the physical resources of our territory for national defence, and for tracing the lines required to form a complete base of operations in time of war, on the assailable portions of our frontier, for which the service had been instituted. Before leaving France, General Bernard had received especial recommendations from the friends of young Poussin to look after his interests, and when they met, therefore, their acquaintance was made on the most intimate and agreeable terms on both sides. Upon the application of General Bernard to the Secretary of War, Poussin was attached to his person as an aid-de-camp, and left Washington with him for a military reconnaissance of the coast on the Gulf of Mexico, and of the delta of the Mississippi. They spent a year and a half upon their important duties, in New Orleans and its vicinity, regardless of the dangers of that climate, and in 1817 returned to the seat of government and submitted to the President a particular and elaborate memoir of their operations. It was upon this first report, presented by the Executive, on the Military Defences of the United States,--a report drawn up in a very large degree by the hand of M. Poussin, and illustrated throughout with his discovery and suggestion,--that Congress, by an almost unanimous vote, authorized the erection of the great line of our military defences, adopting the recommendations of the commissioner without even the slightest alteration. The Board of Military Engineers entered subsequently on the yearly execution of their important duty of examining the coast previous to determining the actual sites and descriptions of the works of defence which they afterwards delineated. The young topographical engineer continued in his arduous scientific labors, and thus contributed largely in the perfecting of that great national scheme. It was in these military operations, and afterwards in the surveys for roads and canals, which, under the supervision of a Board of Internal Improvements, where confided to a portion of the same officers, assisted by civil engineers, that Poussin rendered himself so efficient as a practical and scientific surveyor, and became so perfectly familiar with all the internal resources of our extensive country, which he had thus most remarkable opportunities to study and appreciate, by crossing it in all directions, and, in fact, by visiting every state, and by following up and down every valley and river of the eastern half of the continent. Few men have had such