In 1868 I presented to the Society, on behalf of Sir Charles A. Hartley, a memoir published by the European Commission of the Danube, on the improvement of that river, and at the same time gave a notice of the works designed by Sir Charles Hartley for effecting that important object. These works have now been completed, and Sir Charles Hartley has again asked me to present to the Society a second memoir published by the Commission, which brings the history of the works constructed under their charge down to the time of their completion in 1873.