Page:Popular Science Monthly Volume 74.djvu/439

Rh then at his command, the president reached the conclusion that a canal with locks would best fulfil all requirements, and says in transmitting the board report to the Congress:

When the matter was before the senate committee on inter-oceanic canals, another opportunity was provided for the expression of views by experts. At these hearings. Professor Burr said that he was as strongly in favor of the sea-level canal as he ever had been.

In discussing the Gatun dam, which is a feature of the lock-canal project as adopted, he says:

Continuing, Professor Burr states that he has no objection to earth dams under suitable conditions if properly designed and founded. Anything like a flow of water through the permeable material under the dam should be prevented. No suitable means for accomplishing this are provided in this design. He indicates measures that are ordinarily taken to check the flow of water under a dam, and instances several failures of earth dams. In speaking of the dams near LaBoca resting against Sosa Hill, the construction of which was subsequently undertaken, but owing to the yielding, unstable character of the marsh lands on which they were to rest, have been abandoned. Professor Burr says:

In speaking of the operation of locks, he calls attention to the fact that the experience at the lock at St. Mary's Falls is not a safe guide for reaching conclusions regarding the safety of six such locks as will be required for the Panama Canal. Their lift is 50 per cent, greater,