A few weeks after the address of Major Shelbourne, a paper was read before the American Society of Civil Engineers by Walton W. Evans, in which he described the augmented power of the Sommeiller machine during the excavation of St. Gothard. He said:
Mr. Evans was, We may remember, like Major Shelbourne, in favor of the San Blas route, and the tunnel which that route involves.
Certain details as to the machinery used in the Alps may be of interest. After hand-drilling was given up, all the drills used were run by compressed air, but the methods employed to compress it varied. At Mont Cenis hydraulic power exclusively was used. Sommeiller employed at first the fall of a column of water in the same way in which it is applied in the case of the water-ram. Afterward he substituted turbine-wheels. To compress the air at the St. Gothard, ordinary steam-power was at first used. Afterward the improved method of Sommeiller, the turbine-wheel, was substituted. It was found that the amount of water available at the southern terminus was not as large as at the northern; in the former case, accordingly, a higher fall of water was required. A useful or effective fall, as it is
- "Journal of the American Geographical Society for 1879," p. 240. In the exhaustive report upon the canal problem submitted to the Navy Department in 1883 by Lieutenant J. T. Sullivan, extracts occur from the address of Major Shelbourne. He is our best authority as to the San Blas route.
- "Transactions of the American Society of Civil Engineers," 1880, p. 15.
- Hence, perhaps, the somewhat ambiguous expression used by Mr. Evans, "steam-drills," though it is possible that "steam" is a misprint for "steel." (?)