Central America—West Indian Islands—Geological Notice.
TAKING the natural divisions of the continent alone into consideration,
Central America may be regarded as lying between the Isthmus of Panamá
and Darien and the Isthmus of Tehuantepec, and consequently in a
tropical climate. This narrow tortuous strip of land, which unites the
continents of North and South America, stretches from S.E. to N.W. about
1200 miles, varying in breadth from 20 to 300 or 400 miles.
As a regular chain, the Andes descend suddenly at the Isthmus of Panamá,
but as a mass of high land they continue through Central America and
Mexico, in an irregular mixture of table-lands and mountains. The mass
of high land which forms the central ridge of the country, and the
watershed between the two oceans, is very steep on its western side, and
runs near the coast of the Pacific, where Central America is narrow; but
to the north, where it becomes wider, the high land recedes to a greater
distance from the shore than the Andes do in any other part between Cape
Horn and Mexico.
This country consists of three distinct groups, divided by valleys which
run from sea to sea, namely, Costarica, the group of Honduras and
Nicaragua, and the group of Guatemala.[59]
The plains of Panamá, very little raised above the sea, and in some
parts studded with hills, follow the direction of the isthmus for 280
miles, and end at the Bay of Parita. From thence the forest-covered
Cordillera of Veragua, supposed to be 9000 feet high, extends to the
small but elevated table-land of Costarica, surrounded by volcanos, and
terminates at the plain of Nicaragua, which, together with its lake,
occupies an area of 30,000 square miles, and forms the second break in
the great Andean chain. The lake is only 128 feet above the Pacific,
from which it is separated by a line of active volcanos. The river San
Juan de Nicaragua flows from its eastern end into the Caribbean Sea, and
at its northern extremity it is connected with the smaller lake of
Managua or Leon by the river Penaloya. By this water-line it has been
projected to unite the two seas. The high land begins again, after an
interval of 170 miles, with the Mosquito country and Honduras, which
mostly consist of table-lands and high mountains, some of which are
volcanos.
Guatemala is a table-land intersected by deep valleys, which lies
between the plain of Comayagua and the Isthmus of Tehuantepec. It
spreads to the east in the peninsula of Yucatan, which terminates at
Cape Catoche, and encompasses the Bay of Honduras with terraces of high
mountains. The table-land of Guatemala consists of undulating verdant
plains of great extent, of the absolute height of 5000 feet, fragrant
with flowers. In the southern part of the table-land the cities of Old
and New Guatemala are situate, 12 miles apart. The portion of the plain
on which the new city stands is bounded on the west by the three
volcanos of Pacayo, del Fuego, and de Agua; these, rising from 7000 to
10,000 feet above the plain, lie close to the new city on the west, and
form a scene of wonderful boldness and beauty. The Volcano de Agua, at
the foot of which Old Guatemala stands, is a perfect cone, verdant to
its summit, which occasionally pours forth torrents of boiling water and
stones. The old city has been twice destroyed by it, and is now nearly
deserted on account of earthquakes. The Volcano del Fuego generally
emits smoke from one of its peaks; and the Volcano de Pacayo is only
occasionally active. The wide grassy plains are cut by deep valleys to
the north, where the high land of Guatemala ends in parallel ridges of
mountains, called the Cerro Pelado, which run from east to west along
the 94th meridian, filling half the Isthmus of Tehuantepec, which is 140
miles broad, and unites the table-land of Guatemala with that of Mexico.
Though there are large savannahs on the high plains of Guatemala, there
are also magnificent primeval forests, as the name of the country
implies, Guatemala signifying, in the Mexican language, a place covered
with trees. The banks of the Rio de la Papian, or Usumasinta, which
rises in the alpine lake of Lacandon, and flows over the table-land to
the Gulf of Mexico, are beautiful beyond description.
The coasts of Central America are generally narrow, and in some places
the mountains and high lands come close to the water’s edge. The
sugar-cane is indigenous, and on the low lands of the eastern coast all
the ordinary produce of the West Indian islands is raised, besides much
that is peculiar to the country.
As the climate is cool on the high lands, the vegetation of the
temperate zone is there in perfection. On the low lands, as in other
countries where heat and moisture are in excess, and where nature is for
the most part undisturbed, vegetation is vigorous to rankness: forests
of gigantic timber seek the foul air above an impenetrable undergrowth,
and the mouths of the rivers are dense masses of jungle with mangroves
and reeds 100 feet high, yet delightful savannahs vary the scene, and
wooded mountains dip into the water.
Nearly all the coast of the Pacific is skirted by an alluvial plain, of
small width, and generally very different in character from that on the
Atlantic side. In a line along the western side of the table-land and
the mountains there is a continued succession of volcanos, at various
distances from the shore, and at various heights, on the declivity of
the table-land. It seems as if a great crack or fissure had been
produced in the earth’s surface, along the junction of the mountains and
the shore, through which the internal fire had found a vent. There are
more than 20 active volcanoes in succession between the 10th and 20th
parallels of north latitude; some higher than the mountains of the
central ridge, and several subject to violent eruptions. Altogether,
there are 39 in Central America, 17 of which are in Guatemala—a greater
number than in any other country, Java excepted.
The Colombian Archipelago, or West Indian Islands, which may be regarded
as the wreck of a submerged part of the continent of South and Central
America, consists of three distinct groups, namely, the Lesser Antillas
or Caribbean Islands, the Greater Antillas, and the Bahama or Lucay
Islands. Some of the Lesser Antillas are flat, but their general
character is bold, with a single mountain or group of mountains in the
centre, which slopes to the sea all around, more precipitously on the
eastern side, which is exposed to the force of the Atlantic current.
Trinidad is the most southerly of a line of magnificent islands, which
form a semi-circle, enclosing the Caribbean Sea, with its convexity
facing the east. The row is single to the island of Gaudeloupe, where it
splits into two chains, known as the Windward and Leeward Islands.
Trinidad, Tobago, St. Lucia, and Dominica are particularly mountainous,
and the mountains are cut by deep narrow ravines, or gullies, covered by
ancient forests. The volcanic islands, which are mostly in the single
part of the chain, have conical mountains bristled with rocks of a still
more rugged form; but almost all the islands of the Lesser Antillas have
a large portion of excellent vegetable soil in a high state of
cultivation. Most of them are surrounded by coral reefs, which render
navigation dangerous, and there is little intercourse between these
islands, and still less with the Greater Antillas, on account of the
prevailing winds and currents, which make it difficult to return. The
Lesser Antillas terminate with the group of the Virgin Islands, which
are small and flat, some only a few feet above the sea, and most of them
are mere coral rocks.
The four islands which form the group of the Greater Antillas are the
largest and finest in the Archipelago. Porto Rico, Haiti or San Domingo,
and Jamaica, separated from the Virgin Islands by a narrow channel, lie
in a line parallel to the coast-chain of Venezuela, from east to west;
while Cuba, by a serpentine bend, separates the Caribbean Sea, or Sea of
the Antillas, from the Gulf of Mexico. Porto Rico is 90 miles long and
36 broad, with wooded mountains passing through its centre nearly from
east to west, which furnish abundance of water. There are extensive
savannahs in the interior, and very rich soil on the northern coast, but
the climate near the sea is unhealthy.
Haiti or San Domingo, 340 miles long and 132 broad, has a chain of
mountains in its centre, extending from east to west like all the
mountains in the Greater Antillas, the highest point of which is 9000
feet above the sea. A branch diverges from the main stem to Cape
Tiburon, so that Haiti contains a great proportion of high land. The
mountains are susceptible of cultivation nearly to the summit, and are
clothed with undisturbed tropical forests. The extensive plains are well
watered, and the soil, though not deep, is productive.
Jamaica, the most valuable of the British possessions in the West
Indies, has an area of 4256 square miles, of which 110,000 acres are
cultivated, chiefly as sugar-plantations. The principal chain of the
Blue Mountains lies in the centre of the island, from east to west, with
so sharp a crest that in some places it is only four yards across. The
offsets from it cover all the eastern part of the island; some of them
are very high. The more elevated ridges are flanked by lower ranges,
descending to verdant savannahs. The escarpments are wild, the
declivities steep, and mingled with stately forests. The valleys are
very narrow, and not more than a twentieth part of the island is level
ground. There are many small rivers, and the coast-line is 500 miles
long, with at least 30 good harbours. The mean summer-heat is 80° of
Fahrenheit, and that of winter is 75°. The plains are often unhealthy,
but the air in the mountains is salubrious; fever has never prevailed at
the elevation of 2500 feet.
Cuba, the largest island in the Colombian Archipelago, has an area of
3615 square leagues, and 200 miles of coast, but so beset with coral
reefs, sandbanks, and rocks, that only a third of it is accessible. Its
mountains, which attain the height of 8000 feet, occupy the centre and
fill the eastern part of the island, in a great longitudinal line. No
island in these seas is more important with regard to situation and
natural productions; and although much of the low ground is swampy and
unhealthy, there are vast savannahs, and about a seventh part of the
island is cultivated.
The Bahama Islands are the least valuable and least interesting part of
the Archipelago. The group consists of about 500 islands, many of them
mere rocks, lying east of Cuba and the coast of Florida. Twelve are
rather large, and are cultivated; and though arid, they produce Campeche
or log-wood and mahogany. The most intricate labyrinth of shoals and
reefs, chiefly of corals, madrepores, and sand, encompass these islands;
some of them rise to the surface, and are adorned with groves of
palm-trees. The Great Bahama is the first part of the New World on which
Columbus landed—the next was Haiti, where his ashes rest.
The geology of Central America is little known; nevertheless it appears,
from the confused mixture of table-lands and mountain-chains in all
directions, that the subterraneous forces must have acted more partially
and irregularly than either in South or North America. Granite, gneiss,
and mica-slate form the substrata of the country; but the abundance of
igneous rocks bears witness to strong volcanic action, both in ancient
and in modern times, which still maintains its activity in the volcanic
groups of Guatemala and Mexico.
From the identity of the fossil remains of extinct quadrupeds, there is
every reason to believe that the West Indian Archipelago was once part
of South America, and that the rugged and tortuous isthmus of Central
America, and the serpentine chain of islands winding from Cumana to the
peninsula of Florida, are but the shattered remains of an unbroken
continent. The powerful volcanic action in Central America and Mexico,
the volcanic nature of many of the West Indian islands, and the
still-existing fire in St. Vincent’s, together with the tremendous
earthquakes to which the whole region is subject, render it more than
probable that the Caribbean Sea and the Gulf of Mexico are one great
area of subsidence, which possibly has been increased by the erosion of
the Gulf-stream and ground-swell—a temporary current of great
impetuosity, common among the West Indian islands from October to May.
The subsidence of this extensive area must have been very great, since
the water is of considerable depth between the islands, and it must have
taken place after the destruction of the great quadrupeds, and
consequently at a very recent geological period. The elevation of the
table-land of Mexico may have been a contemporaneous event. In the
Colombian Archipelago, volcanic action is confined to the smaller
islands, which, forming a line in a meridional direction, extend from
12° to 18° N., and which may be designated as the Caribbean range: it
commences with Grenada and ceases with St. Eustatius. St. Vincent, St.
Lucia, Martinique, a great portion of Guadaloupe, Montserrat, Nevis, and
St. Kitts are volcanic; most of them possess craters recently extinct,
which have vomited ashes and lava within historical periods; whilst the
less elevated of the Leeward and Windward Islands, Tobago, Barbadoes,
Deseada, Antigua, Barbuda and St. Bartholomew’s, with the Virgin Islands
and Bahamas, are composed either of calcareous or coral rocks.