WORD LESSON.

The dolphin or dorado is a fish about six feet in length, one of the most active and beautiful of the finny tribe. The back is ornamented all over with spots of a bluish green and silver; the tail and fins are of the colour of gold; the eyes are remarkably large and beautiful, and surrounded with circles of the most shining golden hue. In fact, it is from its appearance that it takes its name-dorado, or golden. Its strength and power of pursuit are represented as amazingly great. It is furnished with a full complement of fins; and such is the power of the muscles with which it is provided, that it can not only cut its way through the water with monstrous rapidity, but can bound to a considerable height, and to the distance of eight or ten yards over the waves. Shoal (from Saxon, sceol, a crowd), a great multitude, a crowd, a throng; generally applied to a multitude of fish. Covey (from Fr., couvée, a brood), an old bird with a brood of young; hence, a small flock or number of birds together; generally applied to game, as a covey of partridges.

SURFACE QUANTITY.-The water on the surface of the globe that does not form part of the ocean is comparatively small, and appears in the form of rivers and lakes-streams of water and pools of water, larger or smaller, and generally fresh. These together hardly cover three-quarters of a million of square miles, but their functions are highly impor

tant.

ORIGIN. Of the rain and snow which fall on the land, part runs in channels over the surface, ever seeking a lower level till it finds the ocean. Part sinks into the earth, fills the fissures of the rocks, sometimes forms extensive subterranean sheets (subter, under, terra, earth), and in time bursts forth to the surface by the most convenient outlets. These outbursts are known as springs. Rivers may originate from one or both of these. Some, as the Ganges, take their rise from immense glaciers-masses of ice and snow melting in summer; but most of them are formed by the union of several streams, flowing from springs till they attain the magnitude of a river.

USE OF SPRINGS.-If the rains were all carried off immediately by surface channels, the earth would be flooded at one time and parched at another. Whereas, sinking into the ground, the. water is stored up for future use, and given out in constant regular supplies. These springs always dissolve some portion of the strata through which they pass, and carry it to the ocean to compensate for the solid matter which marine plants and animals take from it. Likewise, almost every country has springs impregnated with some mineral rendering them medicinal.

VELOCITY AND ACTION.-A river formed in high land may run at the rate of two or three miles an hour in the early part of its course, and may fall from ten to twenty feet for every mile of progress. But as it becomes wider and slower in its way through the law valleys, it often has not a descent of more than two or three inches to the mile, and some

times very much less, as in the case of the Amazon. Sometimes, however, the downward current of a river is strong enough near the sea to produce a dangerous conflict with the tidal wave flowing upward, as in the Indus and Ganges. This is called a bore.

When the channel of a river is narrow, rocky, and much inclined, a rapid is formed; when the rocks are quite precipitous, there is a waterfall or cataract. The most remarkable are those of Niagara, in North America, and of Zambesi, in South-Eastern Africa.

Rivers produce great changes on the surface of the earth, wearing away the rocks, and removing the soil from the higher grounds to the lower. The whole amount of mud and stones they bring down is enormous; and it is often deposited in the form of a delta (A) at the river's mouth. Those rivers that are subject to heavy floods are those that most extensively alter the surface of the land in this manner.

The delta of the Nile is one of the most remarkable, but that of the Ganges is larger. This river is reckoned to deposit at least 6000 millions of tons of solid matter every year. Its delta begins 220 miles from the sea, and has a breadth of nearly 200 miles. Its dangerous bore ascends 60 or 70 miles up its channels.

INUNDATIONS.-Inundations or floods are those overflowings of their usual channels which are caused by heavy rainfalls, or the rapid melting of snows in spring. This may happen at any time in temperate regions, but the heavy periodical rains of the torrid zone occasion regular floods in the rivers, of which

the yearly inundations of the Nile are an interesting example.

Rivers that pass through lakes, as the Rhone, or through wide, open plains, like the Amazon, are much less dangerous in their floods than those with confined channels.

SUMMARY.-The rains which fall on the surface of the earth sink, for the most part, through fissures of the rocks, forming underground lakes. The outlets which these waters find to the surface are called springs, which thus dispense from the internal stores of the earth a regular and constant supply to the surface. Springs form the sources of rivers. These flow with a velocity depending on the incline of their channels; and the sudden irregularities they sometimes meet give rise to rapids, cataracts, and waterfalls. Great are the changes effected by the action of rivers. Slowly, but surely, solid matter is brought from high to low levels; and some rivers, as the Nile and the Ganges, form by this process vast deltas. Inundations occur occasionally in temperate regions, but regularly in the tropical regions, where the rains are heavy and periodical.

QUESTIONS.

How are springs and rivers formed? What is the use of springs? What is meant by a bore; and how is it produced? How are rapids and cataracts formed? Mention some remarkable waterfalls. What changes are produced by the action of rivers on the surface of the earth? Describe the delta of the river Ganges. What is meant by inundation?

THE MOUNTAIN STREAM.

Noble the mountain stream,

Bursting in grandeur from its vantage ground;
Glory is in its gleam

Of brightness-thunder in its deafening sound!
Mark, how its foamy spray,

Tinged by the sunbeams with reflected dyes,
Mimics the bow of day

Arching in majesty the vaulted skies;

Thence, in a summer-shower,

Steeping the rocks around-O! tell me where
Could majesty and power

Be clothed in forms more beautifully fair?

FIRST VOYAGE OF COLUMBUS.

(See Frontispiece.)

A thing of life on the roaring tide,

Seems that fair ship in her strength and pride!
Though howl the winds, though leap the waves,
Her path she ploughs, their wrath she braves;
A fit ship that for that spirit bold,
Who guides her on to a land untold!
Her crew has not a heart that fears
To sail, where bold Columbus steers!
Far, far away from their native shore
That crew are now, to return no more;
About the sails the winds are shrill,
And that to the seamen bodeth ill.
But what bright speck is afar off seen,
Of herb and flowers and welcome green?
Columbus shouts, "Ho, land!" aloud-
Mistaken hope, 'twas but a cloud!
"He plays us false!" from lip to lip,
A murmur ran throughout the ship;
Columbus heard their whispers breathed,
And saw their daggers half unsheathed !
Nor quailed he, though his pride did sue
For patience to his craven crew;
For three days more will they remain?
They yield--but then steer home again.
The first day pass'd, and the setting sun
Columbus told the goal was won:
"Heave-to!" cried he, "crowd sail no more!
"For see ye not the far off shore?"
And there were lands of lake and wood,
Where living men and women stood!
The joyous crew now leapt ashore,
And blest that spot-"Saint Salvador!"

JAMES BRUTON.