During the seventies a French commission made surveys and investigations on the Isthmus which terminated in the efforts of De Lesseps, who undertook to construct a canal, and, in 1879, called an international scientific congress to consider the project in all its aspects and determine upon a practical solution. The United States was invited to be represented by two official delegates, and accordingly President Hayes appointed Admiral Ammen and A.C. Menocal, of the United States Navy, both of whom had been connected with surveys and explorations on the Isthmus. Mr. Menocal presented his plan for a canal by way of Nicaragua, but it was evident that the Wyse project, of a canal by way of the Isthmus of Panama, had the majority in its favor, and the only question to determine was whether the canal to be constructed should be a sea-level or a lock canal. The American delegates were convinced, in the light of their knowledge and experience, that a sea-level canal would be impracticable, if not impossible. In this they were seconded by Sir John Hawkshaw, a man thoroughly familiar with canal problems, and who exposed the hopelessness of an attempt to make a sea-level ship canal, pointing out that there would be a cataract of the Chagres River at Matachin of 42 feet, which in periods of floods would be 78 feet high, and a body of water that would be 36 feet deep, with a width of 1,500 feet. Opposition to the sea-level project proved of no avail. The facts were ignored or treated with indifference by the French, who were determined upon a canal at Panama and at sea level, resting their conclusions upon the success at Suez, with which enterprise many of those present at the congress, in addition to De Lesseps, had been connected. But the problems and conditions to be met on the Isthmus of Panama were decidedly different from those at Suez, and subsequent experience proved the serious error of the sea-level plan as finally adopted. The congress included a large assemblage of non-professional men, and of the French engineers present only one or two had ever been on the Isthmus. The final vote was seventy-five in favor of and eight opposed to a sea-level canal. Rear-admiral Ammen said: "I abstained from voting on the ground that only able engineers can form an opinion _after careful study_ of what is actually possible and what is relatively economical in the construction of a ship canal." Of those in favor of a sea-level canal not one had made a practical and exhaustive study of the facts. The project at this stage was in a state of hopeless confusion. In spite of these obstacles, De Lesseps, with undaunted courage, proceeded to organize a company for the construction of a sea-level canal.