The Scian and the Teian muse,
The hero's harp, the lover's lute,
Have found the fame your shores refuse;
Their place of birth alone is mute
To sounds which echo further west
Than your sires' "Islands of the Blest."
The mountains look on Marathon-
And Marathon looks on the sca;
And musing there an hour alone,

I dreamed that Greece might still be free;
For standing on the Persian's grave,
I could not deem myself a slave.

A king sate on the rocky brow

Which looks o'er sea-born Salamis;
And ships, by thousands, lay below,

And men in nations;-all were his!
He counted them at break of day—
And when the sun set where were they?

And where are they? and where art thou,
My country? On thy voiceless shore
The heroic lay is tuneless now-

The heroic bosom beats no more!
And must thy lyre, so long divine,
Degenerate into hands like mine?
"Tis something, in the dearth of fame,
Though linked among a fettered race,
To feel at least a patriot's shame,

Even as I sing, suffuse my face;
For what is left the poet here?
For Greeks a blush-for Greece a tear.

Must we but weep o'er days more blest?
Must we but blush ?-Our fathers bled.
Earth! render back from out thy breast
A remnant of our Spartan dead!
Of the three hundred grant but three,
To make a new Thermopyla!

What, silent still? and silent all?
Ah! no; the voices of the dead
Sound like a distant torrent's fall,

And answer, "Let one living head,
But one arise-we come, we come!"
'Tis but the living who are dumb.
In vain-in vain: strike other chords;

Fill high the cup with Samian wine!
Leave battles to the Turkish hordes,
And shed the blood of Scio's vine!
Hark! rising to the ignoble call-
How answers each bold bacchanal!

You have the Pyrrhic dance as yet,
Where is the Pyrrhic phalanx gone?
Of two such lessons, why forget

The nobler and the manlier one? You have the letters Cadmus gaveThink ye he meant them for a slave? Fill high the bowl with Samian wine!

We will not think of themes like these!

It made Anacreon's song divine:

He served-but served Polycrates

A tyrant; but our masters then

Were still, at least, our countrymen.

The tyrant of the Chersonese

Was freedom's best and bravest friend; That tyrant was Miltiades!

Oh! that the present hour would lend Another despot of the kind!

Such chains as his were sure to bind.

Fill high the bowl with Samian wine!
On Suli's rock, and Parga's shore,
Exists the remnant of a line

Such as the Doric mothers bore;
And there, perhaps, some seed is sown,
The Heracleidan blood might own.

Trust not for freedom to the Franks-
They have a king who buys and sells!
In native swords, and native ranks,
The only hope of courage dwells;
But Turkish force, and Latin fraud,
Would break your shield, however broad.
Fill high the bowl with Samian wine!
Our virgins dance beneath the shade-
I see their glorious black eyes shine;
But gazing on each glowing maid,
My own the burning tear-drop laves,
To think such breasts must suckle slaves.
Place me on Sunium's marbled steep,

Where nothing, save the waves and I,
May hear our mutual murmurs sweep;
There, swan-like, let me sing and dic:
A land of slaves shall ne'er be mine-
Dash down yon cup of Samian wine!

BYRON.

SOUND.

Echo, (G.) a reflected sound.
Gamut, (from the Greek letter gamma)
the musical scale.
Medium, (L) the substance by which
sound, light, heat, &c., are trans-
mitted from one point to another.
Plural, mediums or media.
Octave, (octavus, L.) an eighth, or mu-
sical interval of seven degrees, and
therefore of eight notes, the first and
last being counted.
Oscillate, loscillo, L.) to swing, or move
backwards and forwards. Hence also
oscillation.

waves.

Pendulum, (pendeo,L.) a vibrating body suspended from a fixed point, as in a clock.

Propagate, (propago, L.) to spread: when applied to light, sound, &c., it means to impel, or move forward in space, and at the same time to multiply by successive production. Hence propagation.

Scale, (scala, L.) Lit. a ladder. Vibrate, (vibro, L.) to swing; to move this way and that, to oscillate. Hence vibratory and vibration.

SOUND-WAVES, AND THEIR PROPAGATION.

THERE are few things so apt to deceive us as the motion of When we stand upon the sea-shore, and look beyond the line of breakers at our feet, we see wave behind wave, far as the eye can reach, all of them manifestly advancing towards us. It seems as if the sea were gradually

flowing in upon the land. If the tide is advancing, this may be so far in accordance with fact, but the appearance is quite the same even when the tide is receding. It must therefore be a deception. Take another case of wave motion, that of a field of standing corn agitated by the wind. Every one who has been in the country on a windy day in summer must have noticed how waves, not unlike those of the sea, travel visibly over such a field in the direction in which the wind blows. Yet we know that the stalks of corn are not carried out of their places. Each stalk stoops in succession as the wind passes over it, and then recovers itself, partly by its own strength, and partly by the reaction of the other stalks which it strikes. The ears meanwhile go and return with a sort of vibratory or alternate motion. Once more, look what happens when a stone is thrown into a pool. Immediately circular waves, proceeding from the stone as a centre, spread in every direction, each gradually increasing in diameter as it goes. Yet the surface does not become hollow at the point from which all the waves are moving. The fact is, that it is the waves alone which have a progressive motion, the water composing them, like the stalks and ears of corn, has only a vibratory or alternate motion. It simply moves up and down. The same thing is true of the sea itself. The waves move towards the land, the water of which they are formed does not.

In every substance which is elastic, whether solid, liquid, or gaseous, the particles may be thrown into a kind of vibratory motion, similar to the motion of waves. If any part of such a body is compressed, as when a bell is struck by its clapper, the elasticity of the compressed particles urges them to expand again, and by their expansion the force of the blow is conveyed to the surrounding parts. By these the process is repeated, and the impulse transmitted to a still wider circle. Thus the motion spreads in every direction, as the waves do in a pool into which a stone has fallen. But this is not all. The elastic force called into action by compression, does more than restore the compressed parts to their former dimensions. When a pendulum

hanging at rest is drawn to one side and let go, it does not simply return to its position of rest, and there suddenly stop. The reason is obvious. Being in motion when it arrives at that position it cannot stop of its own accord, and therefore goes towards the other side, till gravity first stops it, and then pulls it back. Thus it continues to oscillate from one side to the other. Exactly in the same way, the elasticity of a compressed substance tends to produce oscillation. Compression is succeeded by undue dilatation, to be followed again by compression, then again by dilatation, and so on. Hence the motion caused by striking an elastic body, is a vibratory motion consisting of alternate compressions and dilatations, and propagated in every direction after the manner of waves. Now here is the point which, from its importance, demands special attention. It is this vibratory, wavy motion which gives us the sensation of SOUND.

How the motion becomes a sensation no man can tell; it is one of the mysteries of life, known to God only. Even the structure of the ear, the mere instrument in this strange transformation, is not well understood. But this we do know, that unless some vibrating substance, or medium, is in contact with the ear, no sound will be heard. common medium of sound is atmospheric air. already learned that a bell struck in a vacuum sound.

The most We have gives no

Waves of sound are propagated at different rates through different substances. In air, they travel faster or slower according to the temperature, but the usual rate is about 1120 feet per second, or more than 12 miles in a minute. When a gun is fired, the flash and the report are really simultaneous, and to a person standing close by they appear to be so. But a person at a distance sees the flash a considerable time before he hears the report. Light travels so very fast, that we may suppose it to pass instantaneously from the gun to the eye of the spectator, even though he be several miles away. Sound, however, goes more slowly, taking one second for every 1120 feet it has to travel. If, therefore, we reckon 1120 feet for every second after we