Page:Vol 6 History of Mexico by H H Bancroft.djvu/697

Rh of Lieutenant-commander A. Hopkins and Lieutenant-commander P. H. Cooper, and the statements of the pilots and of the captain of the port, prove that Salina Cruz is preferable to La Ventosa for the purposes of a port of entry.

A breakwater 1,500 or 2,000 feet long, and s. 67° ., will protect this Salina Cruz port, and convert it into a snug harbor.

I apprehend no difficulty in constructing this breakwater with the suitable material at hand. The artificial port at Algiers is not unlike Salina Cruz with regard to the nature of its exposure, but very different as to the violence of the sea, which is milder at Salina Cruz.

I believe that the swell entering the roadstead is due to lateral transmission, and absolutely there is no swell by reflexion. I went on board the Cyane during a heavy swell, and observed its motion along the coast, and immediately after landing I ascended to Salina Cruz Point, to watch the swell from a height. The wind was south, but the swell came from the west, and after being considerably broken by a clump of rocks which advance toward the sea at Salinas del Marqués, it was sent out toward the sea.

The transmitted motion reached the Salina Cruz Point, where the swell was distinctly seen to diminish in height, and to enter the roadstead through the crevices in the rocks at Salina Cruz Point and south of the rocks in a north-east direction. A breakwater in the direction proposed above will make this port as smooth as Marseilles, though with much better entrance.

I do not think it will be necessary to construct a jetty on the eastern end of this port, believing that the breakwater will be sufficient to protect an area large enough to shelter forty vessels riding their anchor at two cables' length.

Although the well-known 'Mexican double-current' runs northward and sensibly parallel to the west coast, its influence does not reach the coast itself; and there must be an inner counter-current in close proximity to the land. This fact was unmistakably observed by me during four days, with north and south winds; and the captain of the port states that though the surface-currents coincide with the wind, they are so light as only to affect the course of small boats; the normal currents are from the south-west to the north-east. He has had many years of experience on this coast.

The line of surf begins almost opposite the custom-house, and gradually widens as it advances toward the Morro Point. The absence of surf on the west end of the port illustrates the shelter afforded by the few rocks at Point Salina Cruz, and serves us as an index to what may be expected from a breakwater.

A wharf 300 feet long could now be used for the discharge of vessels during a great portion of the year; but, since they have no wharf, a rope-ferry is used instead.

I do not desire to convey the idea that it would be easy or inexpensive to convert the Salina Cruz roadstead into a harbor, for the simplest problem of this nature requires special studies absolutely beyond the purpose and means of the expedition.

There is no engineering undertaking more fruitful of mistakes than the formation of artificial harbors, even after protracted study and thorough