The Isthmus Line to the Pacific [pp. 259-266]

1849.] TThe Isthmus Line to the Pacific. 261
from time to time during four or five months of
the year when the northers prevail.
These winds sometimes blow a week or more
without ceasing, during which time the waves of
the sea are so heavy as to make it in>p ssible for
any vessel to cross the bar. The Mississippisteamer, during the Mexican war was caught off that
coast in a norther. She was at anchor on the outside, and yet the sea ran so high as to cause material damage to that leviathan of a ship. The tops
of her wheel-houses are some 25 or 30 feet above
the water line, yetsuchwas the force of the waves
that they swept away from the tops of them
her boats which had been stowed up there for
safety. The ship herself was also damaged.
On the Pacific side, this Isthmus is washed by
what is called the Gulf of Tehuantepec. The
shores of this Gulf embrace a coast line of some
300 miles in extent; about 250 miles of which.
including the proposed Pacific terminus of the
communication across, resembles in its geological features the coast line of our Southern Atlantic States. Like them it has a chain of long
narrow islands or promontories, now joining the
main land and again separating from it by sounds
or sheets of water as Pamlico, Albemarle and
the like. There are frequent inlets between the
links in this chain, but all of them have the word
"Bar" as a prefix or affix to their names.
The "Boca Barra," literally "the mouth Bar,"
connects the lagoons into which the Chicapa
empties with the Pacific, and this is the proposed
terminus, on that side, for the Tehuantepec route.
I have now before me a chart of the west coast
of Central America, published by the English Admiralty with corrections up to 1843. By this it
appears that from a point nearly opposite to the
city of Guatamala to another near that of Tehuantepec, say 250 miles, there are twenty-odd inlets and breaks in this chain of islands, and there
is only one among them whose name on the map
is without the word'Bar" attached to it.
There are also on this chart the surveys of nine
ports or roadsteads in and about the Gulf of Tehuantepec from the surveys of Captain Sir Edward Belcher, R. N., in 1838, and others. That
officer surveyed the open roadstead of Ventosa
within 20 miles of BocaBarra, and otherplaces in
the vicinity, but I cannot find that the Boca Barra
is by him, or on any chart, or by any other nautical work of authority among navigators, once
mentioned or alluded to in any manner whatever as a place into which vessels may enter. I
have consulted all the English and French Admiralty charts on the subject, and from all I
can learn I am forced to the conclusion that the
depth of water at the Boca Barra does not exceedsix or eight feet, if there be that much.
One of the first steps therefore in the opening
of a way across this Isthmus for passing the commerce from one ocean to another would be the
construction of a harbor on each side. The difficulties in the way of this I consider insurmountable unless with the expenditure of immense
sums.
The Delaware breakwater, though constructed
when a sailor would say, "the water is as smooth
as a mill-pond," and where there are none of
those ocean waves and heavy rollers that came
from the sea to interrupt the work, cost an immense sum. But such a work as the Delaware
Breakwater, as stout as it is, is not at all calculated to withstand the heavy seas that come
across the broad Pacific ocean gathering magnitude and strength as they come.
In order rightly to appreciate the practical
difficulties of making harbors on the sea coast
where nature has refused to form them, or has
shut them up, consider the difficulties of forming
harbors on the northern lakes where there are
none; consider how the commerce of North Carolina has been broken up by the closing of the
inlets on that coast. Sir Francis Drake, you
recollect, passed with his fleet into Roanoke Inlet, which has barely water enough now to float
a skiff. Plans have been proposed for reopening
it; but the attempt has yet to be made. The
Eddy Stone light house is a work exposed to
the full force of the sea; that work, though its
cost was so enormous, is held up by all nations as one of the greatest monuments that the
world affords as to the powers and skill of the
engineer over the waves of the sea-and yet that
work is a work of pigmies in comparison with
what is required to open a harbor in the Gulf of
Tehuantepec.
Eddy Stone is built on a rock-Tehuantepec
rests on the sand.
Numerous streams empty into the Gulf of Tehuantepec, and as is the case on our Atlantic
coast wherever such streams empty directly into
the ocean, bars, sand spits and islands are the
consequence. The sediment that is brought
down the Mississippi, the Roanoke, &c., is met
at the mouth by an opposing current from the
tide and swell of the sea. Here it is arrested in
its course and held in still water for a moment,
when the process of deposition immediately commences. It is this deposition which, in the course
of time, forms these bars, &c. The indications
are conclusive, that the same geological or drift
agencies which formed the chain of islands along
| the coast of Carolina and Georgia are now at
work in the Gulf of Tehuantepec.*
* See a valuable paper on the subject of drift, formation
of shoals and the like by Lieut. Chas. Davis, U. S. N.,
read before the society of the American Association. Philadelphia, 1848.