Imágenes de página
PDF
ePub

winds, because they moch facilitate trading voyages. The Spanish flotillas, which sail annually from Acapulco, on the western coast of Mexico, to the Philippine islands, are borne along by the trade winds with uninterrupted prosperity ; no attention, no skill, is required to steer them; no accident ever befalls them; and this voyage of nearly half the circumference of the globe, is often performed in sixty days, without a change of sails. It is impossible ever to return by the same track.

In the Indian Ocean the regular trade wind prevails between the southern Tropic and the 10th degree of south latitude ; but to the north of this last boundary, begios the empire of the monsoons. For six months, from April to October, a strong wind blows constantly from the southwest, bringing with it rain and tempest; during the rest of the year, a dry and agreeable wind blows from the northeast. The change from one monsoon to the other is ac companied with violent storms and hurricanes.

All the islands between the tropics are refreshed by the sea and land breeze. During the day a breeze always blows from the sea; but at night it changes, and blows from the land.

Questions. 1. In what part of the world are the winds variable ? 2. In what part are they regular? 3. In what direction do the trade winds blow ? 4. Where do the trade winds prevail ? 5. Which is the easiest voyage, from Mexico to the Pbilippine islands, or from the Philippine islands to Mexico? 6. lo what direction do the monsoons blow? 7. Where do the monsoons prevail ? 8. What is the state of the weather during the southwest monsoon ? 9. How is the weather during the northeast monsoon ? 10. What is the weather during the change of the monsoons ? 11. Which way does the wind blow on the islands of the torrid zone during the day? 12. Which way during the night?

CURRENTS. The great currents of the ocean generally run from east to west, following the course of the trade winds la passing, however, along the shores of continents and islands, they are often diverted from their natural course. Thus the great current which comes across the Atlantic ocean, proceeds between South America and the West India islands into the gulf of Mexico, and then rushes out with great velocity between Cuba and Florida, and proceeds north along the coast of the United States, and northeast as far as the shores of Iceland and Great Britain. This current is called the Gulf Stream. There is a current which comes from the Frozen ocean between Norway and Greenland, and passes along the western coast of Graet Britain, into the English channel. It then turns east, and rushes through the straits of Dover into the North sea. In the Pacific Indian, an Southern Atlantic oceans, the currents, with few es ceptions, run from east to west.

Questions. 1. In what direction do the currents of the ocean generally run ? 2. What occasions a deviation from this course in some instances ? 3. Describe the course of the Gulf Stream. 4. What is the course of the current which comes from the Frozen ocean between Norway and Greenland.

VOLCANOES AND EARTHQUAKES. Volcanoes are burning mountains, with apertures, out of which are thrown with dreadful explosions, ashes, smoke, mud, fire, red hot stones, and lava. More than 200 volcanoes have been discovered, scattered over the surface of the earth, and there are probably many others in parts not yet explored. They may be compared to chimneys, through which the immense fires which rage in the bowels of the earth fiod vent. The most celebrated volcanoes are Mount Etna, in Sicily; Vesuvius. in Italy; and Hecla, in Iceland. The lofty peaks of the Andes in Souih America are one row of volcanoes, extending through New Grenada, Peru and Chili. The most terrible eruption of a volcano on record, is that wbich happened in 1815, in Sumbawa, one of the Sunda islands. The explosions were heard at the distance of more than 900 miles, and the ashes fell in such quantities, as to produce utter darkness, at the distance of 350 miles.

Earthquakes are the effect of the same subterranean fires which occassion volcanoes, and usually occur at the same time. They are commonly preceded by a general stillaess in the air; the shock comes on with a rumbling noise, like that of carriages or of thunder; the ground heaves or rocks from side to side. A single shock seldom lasts more than a minute, but the shocks frequently succeed each other at short intervals for a considerable time. Awful chasms are often made, from which water bursts forth, and sometimes flames. The chasms are sometimes so wide as to overwhelm whole cities at once. Often the earth opens and closes again, swallowing up some people entirely, and squeezing others to death. Sometimes men have been swallowed up in one chasm, and thrown out alive by another. Sometimes houses and farms are carried to the distance of half a mile, and every thing left standing. Sometimes whole islands are sunk in the ocean, and new ones are raised. In 1755, the city of Lisbon was almost wholly destroyed by a great earthquake which extended over a considerable part of the globe.

Questions. 1. What are volcanoes ? 2. What do they discharge ? 3. How many volcanoes have been discovered ? 4. Which are the most celebrated volcanoes in the world ? 5. Where was the volcano which produced so terrible an eruption in 1815? 6. How far were the explosions heard ? 7. How far was tolal darkness produced by the fall of the ashes ? 8. What are earthquakes occasioned by ? 9. How are they usually pre. ceded ? 10. What does the noise resemble ? 11. How long do the shocks last? 12. What are some of the effects of an eartk. quake?

METALS AND MINERALS. Gold is usually found in a perfectly pure state, ai the foot of large ranges of mountains, from which it is washed down by the rivers. The covotries which furnish the most gold are Brazil, Peru, Mexico, East and West Africa, and the islands of Sumatra, Borneo, and Celebes.

Silver. By far the richest silver mines in the world are those of Mexico and Pery. In the course of three centuries, it is estimated that they have yielded 316,000,000 lbs, of pure silver. More than nine-ienths of all the silver in the world comes from the mines of Spanish America.

Iron, the most useful of the metals, is very generally diffused. The iron mines which are most extensively wrought are in Great Britain and France. The following table shows the estimated annual produce of iroo mines in different parts of the world.

Country.
1. Great Britain,
2. France,
3. Russia,
4. Sweden,
5. Austria,
6. United States,
7. All other countries,

Quintale.
5,000,000
4,500,000
1,675,000
1,500,000
1,010,000

480,000
1,015,000

Total,

15,180,000

Copper. Great Britain produces more copper annually than all the rest of Europe. This metal occurs also in Norway, Sweden, Austria, and many other parts of the world.

Lead. Great Britain produces more lead annually than all the rest of Europe. There are lead mines also in France, Germany, Austria, Spain and the United States.

Tin is of less frequent occurrence. The principal mines in the world are in Cornwall in Great Britain. It is found also in Saxony and Spain ; and Banca, a small island near Sumatra, is almost entirely composed of it.

Quicksilver. There are no mines of quicksilver of any importance, except those of Almaden in Spain, Idria in Austria, and Guancavelica in Peru.

Questions. 1. Where is gold usually found ? 2. What countries produce it in greatest abundance ? 3. Where are the richest silver mines in the world ? 4. How large a portion of all the sile ver in the world comes from Spanish America ? 5. What country contains the most extensive iron mines ? 6. What four countries yield the greatest quantity of iron ? 7. What country produces most lead ? 8. Where are the principal tin mines in the world ! 9. What island in the East Indies contains tin in great quantities? 10. Where are the quicksilver mines ?

VEGETABLES. The number, size, and luxuriance of vegetables are greatest in the the torrid zone, and diminish as you go toward the poles. Our hemisphere may be divided, as respects vegetables, into four parts, the torrid zone, the southern part of the temperate zone, the northern part of the temperate zone, and the frigid zone.

1. Among ihe most remarkable vegetable products of the torrid zone are, the sago palm, which yields a juice so thick and nutritious, that it is used for food ; the bread fruit tree and plantain, which produce a fruit resembling bread, the teak of India, which is used for ship-building, and surpasses even the oak in firmness and durability; the mighty Baobab, which grows on the banks of the Senegal, and attains a circumference of 60 and 70 feet ; and the great fan palın of India, one leaf of which will cover ten or a dozen men. Mahogany, logwood, the cinnamon, the clove, the nutmeg, myrrh, balsam and frankincense grow only in the torrid zone.

2. The most important vegetables in the southern part of the temperate zone are, the vine, from the fruit of which wipe is made ; the mulberry, which affords the means of making silk; the olive, which subserves many agreeable purposes ; wheat and barley, the grains which yield the most outritious bread.

3. The northern part of the temperate zone comprehends, among other regions, Britain, a great part of Germany, of Russia, New-England and the adjacent British provinces. Wheat grows with difficulty in the higher latitudes of this climate ; but oals, hemp and flax are raised in perfection. The pastures are rich and verdant; and the forests are fine, yielding the oak, the ash, the elm, &c. This region is little favored by nature, but is inhabited by the most active, enterprizing, and industrious body of men on earth.

4. In the frigid zone, and even as low as the parallel of 60°, nature assumes a gloomy and desolate aspect. The pines rear their tall heads, and cover the hills with their constant mantle of dark green. Jo proceeding towards the north, every species of vegetable which yields food to man entirely fails ; and nothing appears but dwarf trees, and a few scattered bushes.

and firs

Questions. 1. In what zone do spices grow? 2. Whal zone is most favorable for the vine ? 3. What zone is most favorable for wheat and barley? 4. In what zone are the pastures richest ? 5. What zone is best for oats, hemp and fax? 6. What zone coutains the most enterprizing and industrious men ? 7. What veg. etables grow in the frigid zone ? 8. What is the teak used for ? 9. What is the sago palm valuable for? 30. What tree affords the means of making silk ? 11. Where does the Baobab grow and what is its greatest circumference ?

ANIMALS. The torrid zone is as luxuriant in its animals as in its vegetables. The mighty elephant here dwells in the depth of ancient forests, while the rhinoceros and the hippopotamus roll their enormous bulk along the banks of the streams. The most ferocious animals in this zone are the lion, the tiger, the leopard, the panther, the ounce, and the hyæna. Here also is the gentle and beautiful antelope, and the useful camel, without whose aid the deserts would be impassable. This burning zone generates swarms of reptiles and serpents of an enormous size. Crocodiles and alligators fill all the great rivers, and are ready to devour the unwary passenger. The largest birds are the ostrich, the cassowary, and the condor. The insects are inconceivably numerous. The lo ousts and flies move in such close and immense armies as to lay waste the earth and drive nations before them. Among the marine insects are the corals, animals iosignificant in themselves, but remarkable for the effects which they produce. They have stony cases which remain after the death of the animal, and gradvally accumulating and adhering to each other, at leogth form large rocks and even islands. The Pacific ocean, from NewHolland to the Friendly islands, is entirely a coral sea, and navi gators are in perpetual danger of striking against rocks of this substance. New-Holland is in a manner walled round with coral rocks, which render the navigation very dangerous.

In the temperate zone there are very few monstrous or fero cious animals; but the horse, the ox, the sheep, and other valuable domestic animals are found in great perfection nearly to the 60th degree of latitude,

As we approach the 60th degree of latitude, the country, almost deserted by man, is covered with the elk, the martin, the sable, the beaver, the ermine, animals protected from the cold with a covering of rich and beautiful fur, which is eagerly sought after by man for purposes of comfort and luxury, and hence these frozen countries have become the region of an extensive fur trade. The most useful domestic animal in this climate is the reindeer.

In the frigid zone the quadruped species again assume a fierce and formidable character. The bear stalks horrid amid his frozen solitude, and fiercely defends it against the daring approach of man. But the great scene of life over the polar regions is in the ocean. It is here that the mightiest of the animal creation, the enormous whale, rolls through the sea, and mingles his frightful roarings with the sound of the tempest. Besides these lords of the ocean, the Northern seas swarm with herrings, which, during the winter, proceed in vast shoals to the seas of the temperate zone, where they afford the foundation of valuable fisheries.

Questions. 1. What are some of the largest animals in the torrid zone? 2. Which are the most ferocious ? 3. Of what use is the camel? 4. What ferocious animals inbabit the rivers of the torrid zone ? 5. Which are the largest birds ? 6. Wbat er

« AnteriorContinuar »