As I said before it was proposed to protect the canal from the waters of the upper Chagres by an immense dam at Gamboa, and for the purpose of controlling the water tributary to the lower Chagres two additional canals or channels were to be constructed on either side of the main canal. Thus, as the river is very tortuous and the axis of the canal crossed it twenty-five or thirty times, many deviations of the former became necessary. In some places the canal was to occupy the bed of the river and in others it cut across bends leaving the river for its original natural purpose of drainage. The difficulty in retaining the floods in these constructed channels would of course be immense, especially in some of the cases where the water rushing along its natural channel is suddenly turned at right angles into an artificial one. Thus it is clear that aside from the enormous expense incident to the removal of the immense amount of earth and rock necessary to complete the canal, that granting all this accomplished, it would be practically impossible to maintain a sea-level canal by reason of the difficulty in controlling the Chagres and preventing the canal from filling up. The canal company finally came to the conclusion that the sea-level scheme was impracticable and it was abandoned, and plans were prepared for a lock system. As seen on the profile there were ten locks proposed, five on each side of the summit level. The summit level was to be 150 feet above sea level and consequently each lock would have a lift of thirty feet. The profile was constructed especially to show the amount remaining to be executed to complete the lock system, and a mere inspection will show the relative amount of completed and uncompleted area along the axis of the canal. To complete the summit cut it is still necessary to excavate 111 feet, 93 feet having already been excavated, through a horizontal distance of 3300 feet. The width of cut at top surface for the required depth at a slope of 1½ to 1 would be 750 feet, but as I said before, at this slope landslides were of frequent occurrence and the slope would probably have to be increased to at least 2 to 1. Granting the necessary excavations made, there would be still the problem of the control of the Chagres river and the water supply for the summit level to provide for. At first it was thought that the water supply could be obtained from the storage of the waters of the Chagres and Obispo, but this idea was eventually abandoned, either from a belief in the insufficiency of the water supply during the dry season, or from difficulties in the way of conveying the water to the summit level.