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The plains in the north-west of Asia and the south of Russia are known by the name of Steppes, which is a Russian word. The steppes contain large tracts of sandy desert interspersed with rich pastures, and salt-water lakes and springs.

A great plain extends over the north of Africa. A considerable part of this is the Great Desert or Sahara, a barren tract of burning sand, 2400 miles long and 900 broad. All this desert is uninhabitable except a few green spots, where there are wells of water, and grass and trees flourish, and which seem all the more lovely on account of the waste which surrounds them. These are called oases.

In North America there is the vast plain of the valley of the Mississippi ; and there are similar lowlands in South America, called pampas. .

Table-lands are plains of greater or less extent, elevated high above the level of the sea. that in central Spain, embracing the two Castiles ; the region of central Asia, between the Altai and Himalaya range, including Tibet and the deserts of Cobi and Shamoo (the table-land of Tibet is 15,000 feet above the level of the sea); the table-land of Iran, or Persia; the table-land of Mexico; and that of Quito,

; between the Andes of Peru and Columbia.

Down the sides of mountains and hills flow the rivers, fed by the melting of the snow upon the mountain summit, or by the springs of water in high ground. These collect tributary streams from the sloping lands through which they pass, and at last empty themselves into the ocean. The Rhine and the Rhone both take their rise in the mountains of Switzerland, and flow, the former north ward into the

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German Ocean, the latter southward into the Mediterranean Sea.

Water is also collected together in lakes, which often have a river passing through them, as the Rhone through the Lake of Geneva. The largest rivers in the world are in America. Among these are, in North America, the Mississippi and the St. Lawrence, of which the latter rises in the Rocky Mountains and passes through a series of immense lakes, into the Gulf of St. Lawrence; in South America, the Orinoco and Amazon, both of which have their rise in the Andes, and empty themselves into the Atlantic Ocean.

Very large lakes are also called inland seas. Such is the Caspian Sea in Asia. Both lakes and inland seas are often salt; and this is a beautiful provision to furnish this necessary article to persons dwelling in countries remote from the ocean.

Some seas are connected with the ocean only by narrow straits. Such is the Mediterranean, communicating with the Atlantic by the Straits of Gibraltar; and the Black Sea, which opens into the Mediterranean by the Straits of the Dardanelles.

The ocean is really all one, but the parts of it between Europe and America are called the Atlantic Ocean, and that between America and Asia the Pacific.

Other portions of it have particular names, as the Indian Ocean, the Yellow Sea, and the like.

The line of coast is varied by recesses, called gulfs and bays ; and by headlands jutting into the sea, called capes and promontories. .

Such are some of the most striking features of the globe on which we live. How admirably adapted to furnish support and enjoyment to those who live upon it! And as the surface is diversified, so are both the plants and animals which occupy it. There are plants and animals of land, water, and air. Some can subsist only in the frozen regions of the pole ; others, in the glowing heat of the tropics. The rivers fertilize the plains, and so make them provide sustenance for man and beast; and at the same time carry

; forth all impurities to that vast receptacle, the ocean. And connected with the varieties of land and

sea,

hill and dale, are all the diversities of climate upon the earth, each of which fulfils its own purposes, nourishes its own plants, and supports its own animals, while all furnish to man an inexhaustible store of varied blessings, and render back honour and praise to Him who formed them.

LESSON 106.

OMNIPOTENCE.
The Lord our God is full of might,

The winds obey His will;
He speaks, and in His heavenly height

The rolling sun stands still.
Rebel, ye waves, and o'er the land

With threatening aspect roar !
The Lord uplifts His awful hand,

And chains you to the shore.
Howl, winds of night, your force combine,

Without His high behest,
Ye shall not, in the mountain pine,

Disturb the sparrow's nest.
His voice sublime is heard afar,

In the distant peal it dies;
He yokes the whirlwind to His car,

And sweeps the howling skies.

Ye nations bend, --in reverence bend;

Ye monarchs, wait His nod;
And bid the choral

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ascend
To celebrate your God.--KIRKE WHITE.

LESSON 107.

THE ATMOSPHERE.

THE Atmosphere is the whole body of air which surrounds the earth. It forms a kind of outer covering,

. from 40 to 50 miles high.

Air is a fluid, and birds move in it by their wings as fishes do in water by their fins. So the atmosphere may be described as one vast sea extending over the whole surface of the globe. It has its currents and streams, both warm and cold. The winds are the currents, and the whirlwinds, the eddies in this sea of air.

The air being heavy presses down the lower parts by the weight of the upper, and the particles are more closely packed; the air is denser. So the atmosphere is thinner, or, as it is generally called, rarer, the higher we ascend from the surface of the earth. In the same way, water at a considerable depth is more dense than near its surface.

The atmosphere is of important service to the inhabitants of the globe, and is one of those marvellous contrivances which attest the Hand of an All-wise and Beneficent Creator.

1. It is mainly instrumental in supporting both animal and vegetable life. Atmospheric air is made up of two substances mixed together in exactly that

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way which is best adapted to this purpose.

Animals as they inhale * it, are continually consuming one of its ingredients, and exhale in return a vapour which, if breathed without mixture, would be destructive of animal life. This very vapour is that which vegetables inhale during the day, while they exhale the original ingredient fitted for animals to consume again. During the night, however, the reverse takes place in vegetables, which then inhale and exhale the same vapours as animals do. Hence a plant in a room is wholesome in the day-time, but unwholesome at night.

2. The atmosphere is the agent of conveying sound. “The air,” it has been beautifully said, “is the 'carrier of sound ;' and so also the bearer of speech, the means of communicating ideas, of maintaining social intercourse among men.

The earth robbed of its atmosphere presents itself to the imagination as a desert brooded over by silence.” †

3. The atmosphere collects and diffuses heat. The higher we are above the surface of the earth, the more rare the air becomes, and therefore there is less heat. Hence in ascending mountains we find it become continually colder, and snow lies throughout the whole year upon the tops of high mountains at the equator.

4. It also diffuses light; and so places upon which the sun does not actually shine, are lighted up. In a cloudy day it is still light, because light is diffuser by the atmosphere and by the clouds.

5. The weight of the atmosphere causes a consider

* To inhale, is to take in by breathing ; to exhale, to give out by breathing.

† Humboldt.

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