veys. The complications arising from littoral alluvium often require to destroy a whole series of plans, and to start upon a new system, with loss of time and heavy expenses.
With regard to Salina Cruz, I know nothing about the difficulties to be encountered in the foundation of the breakwater, and next to nothing about the nature, intensity, and effects of prevailing currents and winds. The data I have been able to compile have been given above, and all I can say, as an expert, is, that taking into account the results of surveys and other information obtained, and having inspected the localities referred to, I am not able to see anything impracticable in the proposed formation of this harbor.
Judging by comparison, I believe I am safe in stating that the sea-works performed in many places appear to me to have been constructed on a scale greater than their importance warrants, when they are compared with Salina Cruz as the terminus of this ship-canal. Thus:
Antibes. — Has a double mole, one of them 24 feet above the sea, protecting the harbor against the mistral winds. It has been a most expensive work, requiring many additions to the original plan, as well as corrections.
La Ciotat. — Which, like Cherbourg, struggles against reflected swells.
Cannes. — Where the sand-deposits will forever give trouble.
Olonne. — Port of Sands; open to the south-west winds, with protection against lateral transmission.
Inlands of Yea and Ré. — In the latter, the ports of Saint Martin and La Flotte have given a great deal of trouble, with complications that could not be foreseen before the construction of their moles.
I might mention eight or ten other artificial harbors of a limited commercial influence, whose importance is insignificant when compared with that of Salina Cruz.
Should the commerce of the canal assume such dimensions as would crowd the harbor of Salina Cruz, it can be easily conceived that heavy expenditures would be warrantable in the construction of a channel from the canal to the upper lagoon.
Permanency of the Works and Safety of Transit. — Taking for granted that the dimensions to be given to the canal and accessory works will be such as will fulfil the laws of their stability, the only forces that will conspire against their permanence are the necessary wear and tear incident to the nature of the works, accidents, and cataclysms. The former cannot be avoided, and the engineer has nothing to do with the latter. But it will be well to say that earthquakes are not unfrequent in the isthmus, although I would state that they are not as dangerous as is popularly believed. Their damages have been circumscribed to small localities, and their effects upon the canal, may be considered under two points of view: 1. The immediate damage that the canal itself may suffer; 2. The result of these damages, as they may affect the character of inundations, and destruction of life and property.
Since the feeder and the north branch of the canal are to be built upon the valleys of large watercourses, and using the water of the same valleys, no damage to property nor destruction of life can be anticipated, as inherent to the artificial channel. On the Pacific side, the land being flat, no torrents can be formed; and its many and large watercourses will carry the water from the feeder to the sea.
