SONG OF FIRE.

SOMETIME prisoned at the centre, with my throes I shake the sphere;
Through the snowy-topped volcanoes at the surface I appear;

Then I burst through chains that bind me, startle mortals with my power,
Over prairies wide I scurry, feed on forests, towns devour-
Strike the ships midway in ocean, and the teeming towns devour.

FIRE they call me. I am father of the granite rocks that lie
Ages deep beneath the mountains, unperceived of mortal eye;

At my breath they sprang to being, at my touch their crystals came,
That were merely shapeless atoms ere I kissed them with my flame-
Fre with ardor I embraced them, ere I kissed them with my flame.

Rarest gems of countless value, nuggets of the yellow gold
That, through all the time historic. men and empires has controlled,
And the grim and swarthy iron, conqueror on land and sea,
With the many meaner metals, owe their birth and shape to me-
Gleaming ores and dazzling crystals owe their birth and shape to me.

When the rolling of the thunder strikes the trembling wretches dumb,
When the vision-blinding lightning rends the murky clouds, I come.
Fear attends me, horror after, ruin round me wide I cast;
Men my name with bated breathing mutter when my steps have passed--
Gazing voiceless on the ashes where my terrible steps have passed.

Rear they palaces of beauty, fair without and rare within,
Stores of hand-work, filled with fabrics, wealth and profits hard to win,
Temples grand, with costly altars, where the wretch for sin atones-
I appear, and they are ruins, shapeless heaps of blackened stones-
Molten metal, crumbled columns, timbers charred, and blackened stones.

Not alone on land I smite them; but with red, devouring lips
On the ocean sate my hunger with their richly freighted ships;
Swarthy sailors, pallid women, pray in vain for mercy there,
While my crackling and my roaring swell their chorus of despair-
While I dance from deck to mast-head to their chorus of despair.

In the densely crowded city, without pity I affright
Startled wretches roused from slumber in the still and sombre night.
Tenement house or brown-stone palace, either is the same to me;
If they manage to subdue me, gloomy will their triumph be-
Toppled walls upon my foemen tokens of my vengeance be.

Yet malign I am not always: witness for me truly when
I become the humble servant of the toiling sons of men,

Drive the engine, heat the furnace, melt the ore, and soften steel-
Like the monarch in the story, aid the wife to cook a meal-
Monarch, wandering from earth's centre, aid the wife to cook a meal.

Though they see me when the lightning strikes in wrath the lofty domes,
Yet I love to cheer the dwellers in the humble cottage homes;
From the hearth my flickering shadows on the wall I cast at night,
While I crackle-that's my laughter-at the children's wild delight-
As to see those tossing shadows they display their wild delight.

Foe of life have mortals called me-foe to all that breathes or stirs ;
Hence the terror-stricken pagans are my abject worshipers.
Life! there were no life without me; and what time I shall expire
All things growing, all things living, all shall pass away with fire-
Air, heat, motion, breath, existence-all shall pass away with fire.

In the solemn day of judgment, at the awful time of doom,
When all quick and dead are parted, these to light, and those to gloom,
Then the earth that one time bore me, wrapped within my wild embrace,
Shall behold my final splendor as I bear her out of space-
And we twain shall pass together, pass forever, out of space.

TOTHING is more wonderful than the in- | pendicularly against a solid wall through a

and that the action of gravitation upon the ball could be suspended so that it might return to the same orifice through which it had been projected; and if we could, moreover, find any way to close the opening at the instant that the ball reaches it on its return, so as just to intercept it in its passage, and then immediately open the way again for the passage of a second ball-it is evident that if the arrangement of the apparatus for opening and closing the orifice was such as to measure precisely the time that intervened between the changes, we should obtain from it the time required by the ball for its pas

This process would, for obvious reasons, be practically impossible in the case of a material missile rebounding from a wall. We can only

scientific men, and the extent and variety of the resources which they have called into action, for the purpose of eliciting from nature secrets which she would seem to have most effectually concealed. The method devised by a French philosopher for measuring precisely the time required for the passage of a ray of light across a limited space upon the earth's surface furnishes a striking example of this. Some time since an observation was made in California on the velocity with which the electric force is transmitted along a conducting medium, by causing an electric impulse to pass over the wires from San Francisco to Cam-sage to and from the wall, and so could easily bridge, in Massachusetts, and back, without determine the velocity of its motion. interruption, and noting precisely, at the place of observation, by means of a chronoscope, the length of the period which intervened between the instant of its departure and that of its re-imagine it, as an aid to our conceptions in unturn. It was found that the time required for this six thousand miles run was eight-tenths of a second. Now the velocity of light is such that if a luminous impulse had left the place of observation at the same time with the electrical wave, and could have pursued the same track, it would have gone round the circuit five times while its competitor was making one journey. When we contemplate this almost inconceivable rate of motion, the idea of devising any mode of The apparatus by which this result was obactually measuring with precision the time re-tained is represented in the engravings. The quired for the passage of light across any such narrow space as can be made to intervene between any two stationed observers on the earth's surface-as, for example, the length of any line across a plain, or the distance from one eminence to another-would seem to be utterly hopeless. Still the means have been contrived for realizing it.

The principle on which the apparatus was constructed is this:

If we suppose that an elastic ball-of ivory, for example, or steel-conld be projected per

derstanding the analogous operation in the reflection of light. For light can be so reflected as to return in precisely the same path by which it came; and the precise interval necessary between making an opening, to allow it to pass, and then closing the opening to intercept its return, may be measured and marked with as much accuracy as can be attained by any measurement whatever.

rapid opening and closing of a passage for the light is effected by the revolution of a wheel with its periphery divided into teeth of a rectangular form, with interstices between them of the same breadth as the teeth, as shown in Fig. 2, where a little star of light is seen in one of the middle interstices.

The general arrangement of the apparatus is shown in Fig. 1. The star represents a lamp or other powerful source of light, the rays of which, entering the branch tube, are made to converge by means of suitable lenses, until they

INVEIGLING NATURE INTO A DISCLOSURE OF HER SECRETS.

AT REST.

fall upon the inclined glass M, by which a portion of them are turned into the long part of the tube. This long arm points in the direction across the country, toward the eminence on which the other part of the apparatus is placed,

Only a portion of the rays are reflected by the plain glass, for it is not silvered, and so does not act perfectly as a mirror. A sufficient portion, however, of the beam is turned by the polished surface of the glass to answer the purpose intended. The reason why the glass is not silvered, so as to reflect a larger portion of the rays, will appear presently.

INTERCEPTED.

tube will see the light from the lamp reflected from the distant mirror after it has had time to traverse the whole distance between the two stations twice-that is, in going and returning. The light would obviously pass in a continued stream so long as the wheel remained at rest in such a position as to leave the passage open, and the observer would have upon the retina of his eye a steady and continuous image of the light.

But now let us suppose that the wheel begins to revolve. In this case the light, instead of passing continuously in a uniform stream, will form a succession of flashes, its passage being intercepted, and its way opened again, alternately, in rapid succession, by the passing of the teeth and the open spaces between them, in the periphery of the wheel.

Now the thing to be done, in making an observation on the velocity of light with this apparatus, is to cause the wheel to revolve with the degree of speed necessary to produce this

The rays continue their convergence after reflection, as shown by the dotted lines within the tube in the engraving, till they come to a focus, and then diverge again, and pass as they issue from the tube through another lens, by which they are made parallel. In this condition they traverse the intervening country, between the two observers, for a distance of several miles, to the remote station, where the oth-effect, namely, that each flash of light shall go er portion of the apparatus, shown on the left in the engraving, has been previously fixed. This other portion consists of a tube closed by a plain mirror at the remote end of it. The ray of light, after traversing the intermediate country, enters this tube, is reflected by the mirror, and then returns in the same path by which it came, re-enters the tube from which it issued, is made to converge by the lens at the end of it, as shown in the engraving, and after passing the focal point reaches the inclined glass which first received it from the lamp. This glass, of course, reflects a portion of the returning light back toward the lamp; but, not being silvered, it allows a considerable portion of it to pass through to the end, where the beam, after being suitably prepared on its way by lenses, is received by the eye of the observer.

The toothed wheel, together with the clockwork of multiplying wheels by which it may be made to revolve with any required velocity, is seen in its place in front of the inclined glass, and at, or very near, the focus of the transmitted beam of light. If now the wheel is supposed to be at rest, and is in such a position that one of the interstices between the teeth is in the centre of the tube, so that the slender filament of light which the beam forms when near the focus can pass on its way out, and also repass on its return, the eye at the end of the

to the distant mirror and return in precisely the time that is required to bring a tooth of the wheel up into its path and intercept it in its passage back toward the eye. If in this way the first flash which went out through the first interstice would be intercepted by the first tooth, the second would be intercepted by the second tooth, the third by the third, and so on all around the wheel-provided always that the rotation of the wheel continued uniform. The result would be that no light whatever would come to the eye of the observer. If, on the other hand, the revolutions of the wheel were not so timed as that there should always be a tooth ready in the passage to intercept every flash in its return, a greater or less portion of the light would make its way through to the eye, and vision more or less distinct would follow.

Of course when the wheel is in motion a part of the outgoing light would be intercepted by the intervention of the teeth, which would allow the transmission of only a succession of flashes, equal in amount to half the quantity of light that would otherwise pass. The intermittent effect, however, would not be communicated to the eye of the observer. The intervals would be too brief for the eye to take cognizance of them, on account of what is termed the persistence of vision. The eye would see the star of light as before, only somewhat dimmed, as shown in Fig. 3.

When, at length, the rotation reached the two eminences which were chosen as places of point necessary to cause each tooth to catch observation were Montmartre and Suresne, the and intercept on its return the flash which went stations being about five miles apart. out through the opening which preceded it, the light would entirely disappear, and the appearance would be as represented in Fig. 4.

It may, at first thought, seem surprising that the undulations formed in the luminiferous ether, or whatever the motions may be that are To determine, then, the velocity of light by formed by the going and the returning beam, this instrument, all that is necessary is to know can traverse, in contrary directions, precisely the the distance between the two stations, to place same path, for so long a distance, without the the light, and then by the proper adjustments least interference with each other. But this is so to regulate the position of the tubes as to no more wonderful than that of the thousands direct the beam into the tube at the remote of lights in the girandoles and chandeliers of a station, and to receive it in the other on its re-ball-room, or other brilliantly illuminated apartturn, and then gradually to increase the rapid-ment-each one can find its way across the inity of the revolution of the wheel, until each tervening space, undisturbed in the most delitooth shall arrive in succession in the axis of cate inflections of its movement by any interferthe tube just in time to intercept on its return ence of the rest. the flash which was allowed to pass through the interstice which preceded it. In this way, although the light is allowed to go out in flashes to the remote station, and to return after being reflected to the tube from which it issued, it is all intercepted there, and none comes to the eye of the observer.

The mechanism connected with the wheelwork shows, by two dials, each with its index, seen at the side, how many revolutions the wheel makes in a given time; and from this, taken in connection with the number of teeth on the wheel, and the distance between the two stations, the rate at which the luminous undulations must have moved is easily calculated.

It can easily be conceived how delicate the mechanism, how nice the adjustments, and how extremely careful and skillful the manipulation must be, to obtain any satisfactory results with such an apparatus as this. The method was devised by a French philosopher, Fizeau, many years since, and an experiment was made by means of it in the neighborhood of Paris. The

In the experiment made with the apparatus of Fizeau, in the vicinity of Paris, it was found that the wheel by which the light was allowed to pass out through the open spaces in the periphery must be made to revolve at a little more than twelve times in a second, to cause the tooth following each opening to intercept the flash which issued from that opening on its return. There were seven hundred and twenty teeth in the whole periphery, and by the proper calculation made from these elements, including the ascertained distance between the two stations, the velocity of light was found to be about 190,000 miles in a second. The substantial correctness of this result was confirmed by its near agreement with a determination of the velocity of light that had been previously made by computations from certain observed astronomical phenomena; and this correspondence has since been made much more near in consequence of certain discoveries recently made, which have considerably modified some of the astronomical data.

ANTEROS.

66

BY THE AUTHOR OF "GUY LIVINGSTONE," "SWORD AND GOWN," "SANS MERCI,”
"BREAKING A BUTTERFLY," ETC.

CHAPTER XXV.

sands of women have carried such a secret to their graves; thousands, doubtless still walking

OUBTLESS, on that October afternoon, blamelessly through life, are laden with the same;

covery; but you are not to suppose that she thenceforth incessantly brooded over it. She had a dauntless temper of her own, and the mere knowledge of impending danger was sufficient to arouse the stubbornness inherent in her blood; certainly she acknowledged now that the links binding her fate to Caryl Glynne's were not so completely severed as she had fancied, and that he had not been far from the truth when he feared" all was not over between them; nevertheless, supposing that this were so, and that they met ever so often, was there any reason that she should betray herself to others, and, most of all, to him? Thou

weaker than her

While she mused on these things there rose up in her, not seldom, a spir akin to defiance. From one question only she shrank in fear and shame.

How would it fare with her husband if he could guess the truth?

It seemed impossible-utterly impossibleto take him into her confidence now; and yet the time had been when this had not seemed so hard. Lena was blessed-or afflicted, if you will-with a remarkably good memory. She could have repeated, almost word for word, what had passed when she plighted her troth to Ralph Atherstone.