Page:Popular Science Monthly Volume 74.djvu/424

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
420
THE POPULAR SCIENCE MONTHLY


PSM V74 D424 Seagoing suction dredge ancon at cristobel.png

Seagoing Suction Dredge Ancon taking on Coal near Dry Dock at Cristobel. This and other photographs are from the Annual Reports of the Commission.

of adequate data was sorely felt by the members of the commission and it was soon found that no satisfactory conclusion could be reached without supplementing by additional exploration with the auger and otherwise, the information disclosed by records of surveys, borings and shafts, which had been made by the engineers of the French canal companies. There had been no explorations to sea-level by shaft or by borings in the central sections of the canal yet this information was now of paramount importance for the determination of safe slopes for the sides of the deep cuts. In the absence of such information no satisfactory conclusion could be reached relating to the amount of material that would have to be excavated to maintain a great open cut at Culebra. The side slopes of this cut must be so flat that they will stand permanently. They should be as steep as they can safely be held in order that the quantity of excavation may not be unnecessarily increased. For the solution of this problem, it was necessary to know not only the character of all material to be encountered down to sea-level, but to a depth of over 40 feet below sea-level. Incomplete or unreliable data would throw more or less doubt upon the conclusions reached.

The commission of 1904, therefore, entered at once upon the collection of additional data and hoped to be able to reach an intelligent conclusion relating to the type of the canal at an early date. The published proceedings of the commission show that on December 8, 1904, seven months after the United States had taken possession of the canal properties, it was resolved to send the committee on engineering, consisting of Professor W. H. Burr, Wm. Barclay Parsons, and Major B. M. Harrod to the isthmus