THE WATERWAYS OF SOUTH AND CENTRAL AMERICA.
“Whole rivers here forsake the fields below,
And, wondering at their height, through airy channels flow.”
—_Addison._
_The Amazon._—Of the many navigable highways in South and Central
America, the Amazon river is by far the most important. Nay, more, this
river, which has a drainage area of 2,264,000 square miles, which has
10,000 miles of navigation for large boats, and which has a width of no
less than four miles at a distance of 1000 miles from the sea, is in
every respect the most extensive and remarkable river in the world.
The average depth of the Amazon river is 42 feet in the upper portion,
and 312 feet near to its mouth. The influence of the tide is observable
at a distance of 400 miles from the mouth of the river, the usual
current of which is about three miles per hour. The flood rise is from
42 to 48 feet above the lowest level. At a distance of 3000 miles from
its mouth the Amazon is only 210 feet above sea level. Reclus has
estimated the average discharge of the river to be 2,458,026 cubic feet
per second.[123]
_The Magdalena River._—The river in Columbia known by the name of
the Magdalena has its rise in the Lagunas de las Papas (Potato Lake),
and is one of the boundary lines of six of the nine States into which
Columbia is divided. The river runs nearly due north from its source
until it empties into the Carribean Sea in latitude 10° 59´ north,
and 70° 58´ west longitude. The length of the river, measured on a
meridian, would be 569 miles, but according to the best information
available the actual length of the stream is about 900 miles. The
Boca de Ceniza is the only mouth of the stream open to navigation,
the depth of water on the bar here varying from 10 to 20 feet. It has
been proposed to construct jetties at the mouth, so that it would be
navigable to the largest ships frequenting this part of the world. A
channel of 40 to 60 feet in depth can be found for a distance of about
20 miles inside the bar.
Natural obstacles have compelled the navigation of the river to be
divided into five different systems—the first, rafts and canoes from
Bateas to Neiva; the second, steamboats, barges, rafts, and canoes
from Neiva to La Noria; the third, steamboats, barges, and canoes from
Caracoli to Barranquilla; and the fourth, barges, sailing ships, and
small ocean steamers from Barranquilla to the ocean.
It was not until 1847 that a really successful attempt was made to
navigate the Magdalena by steam. Between that year and 1852 four
steamers, of American build, were placed on the river. Now there are
twenty-seven steamers regularly employed, besides a fleet of barges.
The natural obstacles to navigation at the bar of the river have led
the Government of Columbia at different times to expend considerable
sums of money in trying to open a canal from the river at Calawar to
Carthagena, known as the Dique. The project has not, however, been very
successful. The distance of this route is about 90 miles, and, although
the four steamers employed upon it by the Dique Company have been
tolerably successful, a large expenditure is said to be still required
to complete the means of transport. As it is, the Government have
dredges constantly at work on this artificial waterway. The Government
are, moreover, canalising the river throughout its entire length,
the cost being defrayed by charges on the traffic, which is steadily
increasing.[124]
The _Desague Real de Huchuetoca_.—This is a vast drain or cut that
has been carried through the Cordilleras, that surround the Valley of
Tenochillan, or Mexico, at Nochistongo, for the purpose of getting
rid of the dreadful inundations which almost periodically came upon
the city of Mexico. The Section of the Desague, for a considerable
distance, is from 1800 to 3000 square metres (19,365 to 32,275 sq.
feet). Its length from Vertideres to the Salts is 20,585 metres, or
67,535 feet. Near the old well of Don Juan Garcia, at the point where
the ridge is highest, the cut in the mountain extends for a length
of more than 2624 feet, to between 147 and 196 feet in perpendicular
depth. For a length of over 3000 feet more, the depth of the cut is
from 98 to 131 feet. Over a great part of the cut, however, the breadth
is said to be by no means in proportion to its depth, so that the sides
are much too steep and are every now and again falling in.
The _Desague_ was constructed between 1607 and 1650, and with its
dykes and two canals leading from the upper lakes, is stated to have
cost 31,000,000 of livres, or 1,291,770_l._ According to Humboldt,
however, 25,000,000 of livres “were expended because they never had
the courage to follow the same plan, and because they kept hesitating
for two centuries between the Indian system of dykes and that of
canals—between the subterraneous gallery and the open cut through
the mountain.” Humboldt adds that “they neglected to finish the cut of
Nochistongo, while they were disputing about the project of a canal of
Tezaico, which was never executed.” The meaning of Humboldt’s reference
to the cost of this undertaking is rather obscure. One writer has
pointed out that if he means that the necessary cost of the work was
only 6,000,000 livres, or 250,000_l._, there falls to be deducted from
this amount the cost of two other canals—those of Zampango and San
Christobal, begun in 1796 and 1798—amounting to 41,670_l._ more.[125]
This, however, is not at all likely to be Humboldt’s meaning, since
he elsewhere speaks of the _Desague_ as “undoubtedly one of the most
gigantic operations ever executed by man,” and looks upon it with “a
species of admiration, particularly when we consider the nature of the
ground, and the enormous breadth, depth, and length of the aperture.”
The magnitude of the undertaking may be appreciated by the fact,
mentioned also by Humboldt, that if the _Desague_ were filled with
water to the depth of 10 metres (32 feet), the largest vessels of war
could pass through the range of mountains which bound the plain of
Mexico to the north-east.
Of the other rivers in South and Central America none call for any
special description. Few of them are navigable for any distance,
being—like the Chagres river, which traverses the Isthmus of Panama,
or the San Juan river, that is to be utilised for the Nicaraguan
canal—too rapid, tortuous and subject to floods, to be convenient
for purposes of navigation. In course of time, however, as wealth
and population increases, we may naturally look for the artificial
improvement of such waterways with a view to their adaptation for
purposes of commerce, as in the European rivers already referred to.
FOOTNOTES:
[123] Van Nostrand’s ‘Magazine,’ vol. xxiv. p. 66.
[124] Further details as to the navigation and traffic on the
Magdalena may be found in the U.S. Consular Reports, No. 47, 1884,
pp. 334-348.
[125] Pitman’s succinct view and analysis of authentic information
extant in original works, on the practicability of joining the
Atlantic and Pacific Oceans by a ship canal across the Isthmus of
America. London, 1825.