페이지 이미지
PDF
ePub
[graphic]

SECTION I. The Mighty Deep. What do you understand by the phrase, THE MIGHTY DEEP, so often applied to the sea—that great body of water, which we behold stretching away before us, apparently without end or boundary ?

The term has reference to extent and power and depth, the most remarkable properties of that immense expanse of water, of which the Psalmist speaks as "the great wide sea, wherein are things creeping innumerable, both small and great."

We read in the history of the Creation, given in the Book of Genesis, that God said, “Let the waters under the heaven be gathered

B

was so.

together, and let the dry land appear; and it

And God called the dry land earth, and the gathering together of the waters called He SEAS."

If we look at a map of the world, we shall see that about three-fourths of the whole surface is covered with water, more or less surrounded and divided by land. We shall also observe that different names are given to these bodies of water: some, the largest, being called OCEANS, others SEAS;

those which run up into the land a short distance are GULFS or BAYS; narrow channels which connect two larger bodies of water are sTRAITS ;

those are LAKES which are entirely surrounded by land; and those RIVERS, which go winding far inland, it may be hundreds of miles, forming sometimes the boundaries between neighbouring nations, at others the principal means of communication between those divided by long distances from each other. These highways of commerce, and sources of fertility, have their origin in inland springs, or lakes, or in the snows that gather about the peaks and amid the hollows of lofty mountains, and are melted by the summer sunshine. Like the other bodies of water mentioned, they vary greatly in size;

the largest known, the Mississippi, in America, being in length above 3000 miles, while the Thames, the largest English river, is but 240 miles long. Oceanic rivers are those which flow into the sea ; those which run into a lake, or some other river, are termed tributaries, affluents, or feeders.

That is the source of a river where it takes its rise; the portion of country drained by it is called its basin, because it is usually of a hollow shape. Small water-courses we term brooks, streams, and rivulets, and several of these united form a river, of which, again, there may be many which run into one channel, and make what is termed the principal river, whose true source it is often difficult to determine, on account of these numerous tributaries.

The cavity through which a river flows is called the bed ; this may be either soft or hard, deep or shallow, according to the nature of the soil, and the swiftness of the current, whose course is bounded on either side by the banks. These are in some places steep and high, in others low and sloping; they may be clothed with vegetation, or bare and barren, although usually trees and plants grow and flourish there in great beauty and profusion.

A river generally takes its rise in some mountainous region, or table land far above the level of the sea, into which it empties itself, and the swiftness of the current is in proportion to the steepness of the descent down which it flows. Geographers—that is, those who describe the surface of the earth -some. times speak of the upper, middle, and lower courses of a large river. The first is where it passes through the high or mountain land of its source, and here it often rushes with great force and swiftness down precipices and sudden descents, in what are called WATERFALLS and CATARACTS. The middle course lies through hilly districts, which border upon the mountains; here it is often still rapid and turbulent, but not so much so as higher up, and the nature of the ground frequently causes the channel to wind considerably.

The lower course lies usually through broad level plains, thickly peopled and highly cultivated, and here the current, meeting with few obstacles, turns this way and that, following what would be called a serpentine or meandering course; the latter word being derived from the name of the Greek river Meander, which is remarkable for this twisting and winding about, as though it did not like to

« 이전계속 »