such conduct is utterly disgraceful. The new hands have just as good a right to take the wages offered by the masters, as the old hands have to refuse them. Every one has a perfect right to sell his labour for what he pleases; and to resort to force or intimidation in order to deter a man from freely exercising that right, is the height of injustice, cowardice, and oppression. Compiled.

ARETHUSA.

ARETHUSA arose from her couch of snows
In the Acroceraunian mountains-

From cloud and from crag, with many a jag,
Shepherding her bright fountains.

She leapt down the rocks, with her rainbow locks
Streaming among the streams;-

Her steps paved with green the downward ravine
Which slopes to the western gleams:

And gliding and springing she went, ever singing
In murmurs as soft as sleep;

The Earth seemed to love her, and Heaven smiled above her
As she lingered toward the deep.

Then Alpheus bold on his glacier cold,

With his trident the mountains strook;

And opened a chasm in the rocks;-with the
All Erymanthus shook.

And the black south wind it concealed behind
The urns of the silent snow,

spasm

And earthquake and thunder did rend in sunder
The bars of the springs below:

The beard and the hair of the River-God were
Seen through the torrent's sweep,

As he followed the light of the fleet nymph's flight
To the brink of the Dorian steep.

"Oh, save me! oh, guide me! and bid the deep hide me!
For he grasps me now by the hair!"

The loud Ocean heard, to its blue depth stirred,
And divided at her prayer;

And under the water the Earth's white daughter
Fled like a sunny beam.

Behind her descended her billows, unblended
With the brackish Dorian stream:
Like a gloomy stain on the emerald main,
Alpheus rushed behind,-

As an eagle pursuing a dove to its ruin,

Down the streams of the cloudy wind.

Under the bowers where the Ocean Powers
Sit on their pearled thrones;

Through the coral woods of the weltering floods,
Over heaps of unvalued stones;

Through the dim beams which, amid the streams,
Weave a network of coloured light,

And under the caves, where the shadowy waves
Are as green as the forest's night,—
Outspeeding the shark and the sunfish dark,
Under the ocean foam,

And up through the rifts of the mountain clifts,—
They passed to their Dorian home.

And now from their fountains in Enna's mountains,
Down one vale where the morning basks,
Like friends once parted, grown single-hearted,
They ply their watery tasks.

At sunrise they leap from their cradles steep
In the cave of the shelving hill;

At noontide they flow through the woods below
And the meadows of asphodel;

And at night they sleep in the rocking deep,
Beneath the Ortygian shore,-

Like spirits that lie in the azure sky,

Where they love, but live no more.

SHELLEY.

GENERAL PROPERTIES OF LIGIIT.

LIGHT is one of the most beautiful and useful phenomena in the world. It was long a subject of controversy among philosophers whether light consisted of material particles thrown off from luminous bodies, or was the result of undulations or vibrations propagated from the luminous body; but the latter theory is the one now generally held. The general properties of light, however, have long been determined, and are not difficult to apprehend.

Y

Light proceeds from every part of a luminous body in straight lines. This may be shown by causing light to pass through small holes into a dark room filled with smoke or dust. It is proved also by the fact, that bodies cannot be seen through bent tubes; and it may be inferred from the form of the shadows of bodies. Some suppose that transparency is owing to the rectilineal arrangement of the pores of bodies, which enables them to act like straight tubes for the free passage of light; and that opacity is caused by an opposite arrangement, in consequence of which rays are intercepted, as if by bent tubes.

Light diffuses itself more and more as the distance from its source increases. Thus, if a candle be placed behind an opaque screen pierced with small holes over one square inch of its surface, and if a sheet of paper be placed close to the screen, we shall see upon the paper specks of light marking out a square inch. If the sheet of paper be removed further from the screen, the illuminated space will increase; and more careful experiments will show that the increase is as the squares of the distances, and indicates a diverging pyramid of rays. But while the space illuminated increases, the intensity of illumination diminishes, and that, too, in proportion to the square of the distance from its source. At two feet from a candle, a person has only the fourth part of the light which he would have at one foot, at three feet the ninth part, at four feet the sixteenth part, and so on.

Light moves with prodigious velocity. It has been ascertained from various astronomical phenomena—especially from the fact that eclipses and immersions of the satellites of Jupiter become visible fifteen minutes sooner when the planet is at its least, than when it is at its greatest, distance from us-that light travels at the rate of 186,000 miles in a second of time. The light from the sun reaches

the earth in seven minutes and a half-though the distance is such that a cannon-ball, fired with the greatest force from the sun, and continuing its velocity unabated, would require more than seventeen years to traverse the distance.

If a source of light, such as a candle, is brought into a dark room, all the objects in the room are more or less illuminated. Here we have not only the transmission of light in radiant lines or rays from the source of illumination, but also the turning back of these rays, or their reflection from the objects illuminated. It is owing to this reflection of light from their surfaces that bodies which are not themselves luminous become visible to us; and the law which it follows is extremely simple. If the light falls at right angles on any reflecting surface, it returns again at right angles, or in the same line towards the luminous body; but if the rays fall at an angle with the perpendicular of the surface-or, in other words, on one side of that perpendicular— they are reflected at the same angle with it on the side directly opposite.

This law, expressed in scientific language, is that the angle of reflection is equal to the angle of incidence; and it at once explains such familiar phenomena as the following. If I stand before a mirror, I see my image reflected back to me. If I stand a little to the side, I cannot see myself; but a person who stands just as far on the other side of it can see my image in the glass, and I see his. If I place a candle a little to one side, I must go as far on the other to see its image in the glass.

It has been already stated that light passes in straight lines. But this is true only so long as the medium through which it travels preserves the same density and the same chemical nature. When that ceases to be the case, the ray

of light is bent from its course into a new one, or is, in optical language, refracted. Thus, the end of a stick, when put in water appears bent, owing to the refraction which the light suffers in passing from air, a rare medium, into water, a dense medium. If a shilling be put in a basin, and the eye placed so as just to see the edge of the shilling, then if water be poured into the basin, the shilling will be seen most distinctly; for, when no water is in the basin, the rays of light from the shilling, proceeding in straight lines, are prevented from reaching the eye by the side of the basin; but when water is poured in they suffer a refraction in emerging from water a dense medium, into air a rare medium, and consequently proceed to the eye.

P

B

A B, a piece of thick plate glass.

R R', a ray of light which first proceeds in a straight line through the air, then becomes refracted by the glass, and resumes its original direction on passing from the glass again into air.

The general law of refraction is thus expressed :-When the ray passes from a rare to a denser medium, it is refracted towards a line perpendicular to the surface of the latter; and conversely, when it leaves a dense medium for a rarer one, it is refracted from a line perpendicular to the surface of the denser substance. In the former case the angle of incidence is greater than the angle of refraction; in the latter, it is less.

Different bodies possess different refractive powers, and generally the densest substances refract most. Combustible bodies, however, usually possess greater refractive power than their density would indicate; and from observation of this fact, Sir Isaac Newton predicted the combustible nature of the diamond long before anything was known respecting its chemical nature. It is owing to the increasing density of the atmosphere as it approaches the earth, that the sun's rays are so refracted as to cause the sun and moon to appear larger at the horizon than at the zenith. To the same