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“Oh! He told you so when you re

stood that there had been more under peated to him all*that folly which I talked their words than either had cared to utter. about him at Camlough.'

Again the firelight played its weird pranks An involuntary look of disgust crept for about the guest's golden head, and threw a moment into May's eyes. It did not strange meanings into her eyes, and laid escape Katherine, nor was she likely to ominous touches upon her mouth. And forget it when it presently disappeared. again the superstitious, unaccountable

“You are mistaken in me, said May; terror of approaching harm gathered “I could not so betray any one.”

round May's heart; till a welcome house“Ah! that is good of you. Primness, I hold sound in the passage broke the spell, see, sometimes does one a service. I re- and she felt ashamed of herself. member now that I made you promise to “Come!” she said, we are a silly pair forget that conversation.”

to stay here sparring at one another. Don't “I have a better

memory
than

you

think we had better go and be sociable “You have a better everything, my dear, in the parlour ? My aunt is waiting for us, except physique and self-will. I yield to and I want to present you to Mr. Finiston. no one in beauty, and I have a talent for “ Wait!" said Katherine. She had having my own way, which amounts to lighted the only remaining stick of the genius. You shall see it in full working wicked faggots. She held the blazing wood before I have been here long."

in her hand, and watched it burn away May looked up brightly, and laughed at slowly towards her fingers, while a lurking her audacity, which, she yet knew very smile played about the corners of her well, was not a merry jest. After all, this mouth. I am reading your future. I was no unearthly creature of unhallowed am looking to see whether you will be powers not to be baffled; but only wild married to your Paul. Did you ever hear Katherine Archbold. It was her nature of Margaret and her daisy? Well

, if the to do mischief where she could, but May burnt part breaks and drops away

before had a subtle power of her own, of which the flame reaches my finger it is the breakshe was not all unconscious. And she would ing of your engagement. Watch, watch! not fear any other woman on earth, were It is gone!" that other woman incarnate beauty itself. The piece of red charcoal had dropped Something of this Katherine found in the on the hearth. Katherine tossed the burnspeaking dark eyes. So she became more ing morsel that remained into the fire. The offensive.

flames dropped in the grate, and the room Are you desperately in love with your was in darkness. fine Paul?" she asked.

“Don't be a goose !” said May, and “I don't dislike him," said May. opened the door into the lighted passage.

“ Bah !" said Katherine, provoked. “As But Katherine was not accustomed to be if I did not know that you are a soft little called a goose. fool, ready to love anybody!"

May coloured. “Not anybody," she said ; “not you, for instance."

PERIODICAL COMETS. “Oh, she has lost her temper at last. Not me? Well, look here. I will make THE discoveries of modern science lead a bargain with you. You begin to love us to infer that there is a great resemme with all your might, and I will give blance, in many particulars, between the you this pretty ring. It is worth a hun- greatest and the smallest bodies in creadred guineas.

tion; that atoms, like suns, are separated The diamonds flashed in the light of from each other by distances which are the blazing faggots, as Katherine held the enormous when compared with their actual ring poised on the end of her little finger. size; that the molecules composing a bar

May put her hands behind her back. of iron waltz round and round in circlets Keep it,” she said; “I am too poor to or ovals, exactly as Mars, Jupiter, and the give you even the wretched price you ask rest of us, whirl round Phæbus, and for it.”

Phoebus himself and his fellow-stars reKatherine frowned and smiled. “I al- volve round some unknown central point. ways knew you were obstinate," she said, Perhaps some atoms, in bodies called solid, “but you are sharper than I thought you.” may dance up and down, like gnats in

There was sudden silence between the sunshine, the swarm remaining stationary two girls. It was as if both had under-while each gnat keeps changing its place

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in the airy reel ; others may simply vibrate capable of kindling wars, upraising deluges, backwards and forwards, like bullets fixed nor splitting worlds into two or at the tip of a steel spring, and made to pieces. These remarkable bodies someoscillate by being pulled aside from their times throw out tails one hundred millions position of repose.

of miles in length and fifty thousand in Atoms, too, like suns and planets, are diameter. What, however, is the mass of each endowed with their own proper force. matter of which such a prodigious tail conTheir inconceivable minuteness by no means sists ? According to Sir John Herschel, renders them insignificant. They are veri- if it were all swept together and suitably table giants in disguise. The attractive compressed, it might be carted away in a power of Sirius may be enormous, over- single horse-load. Can bodies so infinitely whelming the mind with such questions as, light, we feel tempted to ask, be subject to How much would a pound of lead, weighed the ordinary laws of gravity ? on earth, weigh on the dog-star's surface, Tycho Brahé was the first, in modern if, indeed, it has a surface ? But the times, to find that comets are not meteors energy of many atoms is all but irresistible. engendered in the atmosphere, as held by Freezing water will burst iron bottles into Aristotle and numerous astronomers of fragments. Terrible explosions are often later date. Kepler was of the same opinion, the result of the attraction exerted on each which he illustrated by a striking comother by atoms which are determined to parison, not devoid of plausibility. join company at the first opportunity. No- the sea has its whales and leviathans, it is thing can prevent their ultimate union. naturalthat the air should have its monsters

We cannot suppose the atoms of which and comets, shapeless bodies engendered bodies are composed to be in actual con- from its superfluous dregs by a sort of tact, for in that case their expansion and animal faculty. As to their number, there contraction by heat and cold, and other are more comets in the sky than fish in the causes, would be impossible. And yet we ocean.” They were consequently supposed are unable to force them closer together to be not far distant from the earth. But than they choose to go. Water, so yield. Tycho Brahé, not being able to ascertain ing to the_touch, is very slightly com- the diurnal parallax of the comet of 1577, pressible. Pressure has been tried in vain concluded that it must be further away to permanently augment the density of soft from the earth than the moon. metals. Steam, ice, gunpowder, fulminat- Their movements were still more puzing mercury, afford familiar instances of zling. Kepler supposed that they advanced the power of atoms. In short, the smallest in straight lines; that is, we suppose, in molecules, like the largest stars, are sepa- curves parallel to the surface of the earth. rated by intervening spaces, perform their It was a nearer guess that comets describe allotted motions, and are gifted with a parabolic orbit—if that can be called an strength enough to insure them respect. orbit which is not an orbit (there being no

As the least and the largest bodies re- return), but only a path. This parabola semble each other, so do the lightest and run through by a comet, may be comthe heaviest in their obedience to universal pared to a huge pair of sugar-tongs, with laws. Nothing, to be visible, can be con- legs of infinite or rather indefinite length, ceived lighter than a comet. Had the which could never meet at their tips, even ancients been aware of the excessive levity to grasp and catch the sweetest, solidest, now attributed to them, they would have most inviting of comets. Each comet accounted for their extraordinary conduct came from a sort of nowhere, and, after by that cause.

And yet the circumstance showing itself to the wondering earth, rethat stars shine through comets ought to turned to its nowhere again, lost in the have raised the suspicion that they could depths of the heavens, the abyss of space, not be very dense. And yet, according to beyond the limits of the known celestial some, the moon was once a comet; Saturn regions. also was once a comet. But the moon But unfortunately for such suppositions, or Saturn, either of them, contains matter there is no such place as nowhere, any more enough to make millions of comets. than there is such a fact or process as anni

Had the lightness of comets been known hilation. There is change; which is life. A in former days, it might have dissipated all condition of material unchangeability and fears of their influence in causing either inaction would be absolute death ; instead of political disasters or physical catastrophes. which we everywhere meet with force and Such things of nought can neither be movement. The limbo of poets, if it have a name, has no local habitation discoverable well as its reappearance, predicted by by telescopes. There is no “ behind the our illustrious countryman fifty-four years scenes" in the heavens whence new stars beforehand. So proud was the Oxford and comets may make their entrance and professor of his discovery, that he begs strut and fret their hour on the celestial posterity (now our ancestors) to remember stage; no lumber garret or property that it was due to an Englishman. room into which they can retire and be Edmund Halley calculated the elements stowed out of the way. The universe is of his comet's orbit at its perihelium pasan open, infinite somewhere, at every point sage in 1682, when it blazed in the heavens of its extent as much a real somewhere as with wonderful splendour. He found that it is here, where we happen for the moment orbit to correspond exactly with those of to be bowling through space.

the comets of 1531 and 1607, which led A little thought will, therefore, tell us him to conclude that all the three were one that it is just as interesting to know what and the same individual, making, in 1682, becomes of comets after we lose sight of its third public appearance on the stellar them as to watch their doings while they stage. These three returns of the same are visible.

Tycho Brahé's observations comet gave it a period of revolution of led him to infer that the comet of 1577 about seventy-five years and a half, with a had described round the sun an arc of a variation which might amount to two circle including within it the orbits of years. This incertitude did not prevent Mercury and Venus. Herelius, in spite of Halley from predicting its return in 1758. his erroneous notions respecting the nature Capini was the first to conceive the idea of comets, first discovered that the curves of searching the records of ancient obserin which they moved were parabolic in vations for the orbits of comets, with a their nature; but he appears to have known view to their possible return. If it had nothing—a grand and vital omission of occurred to him to refer their motions to the place occupied by the sun within those the sun's attraction, and to consider the carves, nor of the laws which governed the sun as their centre, he would have made velocities of those bodies as they approached an enormous step in advance. He emthe summits of their parabolas.

ployed the most delicate processes then an immense step when an as- known to astronomy to ascertain when tronomer dared predict that a given comet, comets would reappear, but he had no which he had observed, would one day means of verifying his predictions, because return-a still greater when he ventured to the resemblances which he thought he fix an epoch for its appearance when he found in comets were only apparent. He would not himself survive to witness the ought to have compared their motions by fact. And our interest in the comets referring them to the sun's influence. whose periodical return is well established Halley was the first astronomer to adopt increases with their increasing number. this grand principle, and he signally sueThere appears no reason why this number ceeded in consequence. His method led to should not augment with a rapidity com- the important conclusion that comets are parable to the quickly successive dis- veritable planets. Their movements, which coveries of the telescopic planets circulating appear extremely irregular, are not so when between Mars and Jupiter. At present referred to the sun. The difference be. we are acquainted with eight comets which tween them (considered as members of the have come back to visit us once or several solar system) lies in the form of the orbits times, after their return had been an- they describe, and which, instead of being nounced as probable in consequence of the almost round, like those of the planets

, are circumstances of their previous arrivals. extremely long ovals, which is the reason M. Delaunay, in the Annuaire du Bureau why we lose sight of them during such des Longitudes for 1872, gives sundry lengthened intervals of time. historical details, which we propose to We have seen that there was a margin abridge, relating to the discovery of the of about two years left open for the comet's periodicity of those eight comets.

return. It was an allowance made for the The most important of these in the action of the planets on the comet's course. annals of astronomy is Halley's comet. The exact amount of that action was diffiIt is the first whose periodicity was ascer- cult to determine. Nevertheless, Clairaut tained, and its period of revolution is the set to work to calculate it, in confirmation longest known. Very remarkable also was of his enthusiastic faith in the Newtonian the clue which led to its identification, as system, which was not universally admitted

It was

now is.

then by the world called “learned," as it of the solar system of which we have been

“ The comet we are expecting,” unable to take account-for the comets of he said, in the public sitting of the whose situation and strength we are ignoAcadémie des Sciences, on the 14th of rant-for the resistance of the ethereal November, 1758, “has become the object matter, which we are incompetent to apof much greater interest than the public preciate, and for the numerous quantities asually bestow on astronomical questions. which we are obliged to neglect in an The true lovers of science desire its return, approximative calculation? The difference because the result will be a brilliant con- of five hundred and eighty-six days befirmation of a system (Newton's) in whose tween two revolutions of the same comet favour every phenomenon gives evidence. -a difference produced by the disturbing Those, on the contrary, who delight to see forces of Jupiter and Saturn—is a more philosophers plunged in trouble and un- striking demonstration than one could certainty, hope that it will not come back, have hoped to obtain of the grand prinand that the discoveries of Newton and his ciple of universal gravity. It places the partisans will fall to the level of other hy- law amongst the number of fundamental potheses, which are the offspring of mere physical truths, of whose reality it is no imagination."

more possible to doubt than it is of the Undaunted by this scepticism and oppo- bodies which produce attraction.” sition, which we can hardly understand at Halley's comet was again due in 1835. the present day, he traced the constellations M. Damoiseau, taking into account the it would traverse, and the planets it would disturbance to be caused by Uranus, fixed meet with on its way, and found that its perihelic passage for the 4th of NovemSaturn would retard its arrival by one ber of that year. Another astronomer, M. hundred days, and Jupiter by five hundred de Pontecoulant, predicted for the 13th and eighteen-in all by six hundred and according to M. Delaunay); but M. Leeighteen ; that is, this revolution of the couturier states that M. de Pontecoulant's comet would be a year and eight months calculation gave the 15th of November, longer than the previous one. In other at midnight, as the date. The comet really words, its passage at its perihelium would passed the point of its orbit nearest to the take place about the middle of April, 1759, sun at nine o'clock in the morning of the within a month, more or less.

16th of November, thus failing to keep Never had a scientific prophecy excited the rendezvous given it by so brief a delay greater curiosity from one end of Europe as nine short hours. As the anxious exto the other. The comet did reappear; it pectant was aware of its coming, he profollowed the path through the constellations bably waited patiently, for astronomy can which Clairaut had traced for it; it reached boast of but few more brilliant feats than its perihelium on the 12th of March, 1759, this. just a month before the date indicated. According to the same gentleman's calWe may note that the difference between culations, twenty-seven thousand two huntheory and observation might be caused by dred and seventeen days must elapse bethe action of the planets Uranus and Nep-tween the comet's departure from its tune, of which (as he did not know of their perhelion in 1835 and its next arrival at existence) Clairaut could take no account that point of its orbit; this calculation in his calculations.

appoints the 24th of May, 1910, for that It was a grand triumph for the New- interesting phenomenon to come off. The tonians. “We have all witnessed the arithmetic which hangs about Halley's accomplishment of the event," wrote comet in groups of figures, inconceivable by Lalande, who had rendered great assist- unlearned minds, informs us that for thirtyance in the calculations ; that it is eight years it travels in our direction from placed beyond a doubt that comets are the extreme limits of our solar system to a really planets which turn like the others point distant about forty-eight millions of round the sun. M. Clairaut demanded a miles from the sun; that it then retreats month's grace in favour of theory, and the rapidly, and thirty-eight years afterwards, month's grace has not been exceeded. The leaving Uranus behind it, reaches Nepcomet came, after a period of five hundred tune's orbit, about three thousand millions and eighty-six days longer than its pre- of miles from the sun. These figures are ceding period, that is, thirty-two days far too enormous to convey any definite before the appointed date. But what is idea of distance; but it would be easy to thirty-two days for the various attractions calculate how many years it would take a

SO

was

racehorse to gallop round this course from time of its perihelic passage. But in 1846, the starting point, its perihelion, back again astronomers, without any reproach to their to the winning-post, the perihelion also. sobriety, saw it double. It was two comets,

So much for the comet's excursions into travelling side by side, with a tendency space. It was natural to trace it back re- rather to quit than to approach each other. trospectively into the night of ages. The The quarrel, too, had come on suddenly; result has been to establish, with more or shortly before its complete accomplishless certainty, that our coy visitant has ment, such observers as Maury, of Washbeen detected, at sundry intervals agreeing ington, and Challis, of Cambridge (Engwith the periods required, up to October of land), declare that they saw no symptoms the year 12, B.C.

of the separation. The disunited couple Encke's comet, named after the cal. are expected back in the autumn of 1872, culator of its elements, completes its revo- and we shall be curious to see whether lution in about three years and a half. they have made it up, and behave as beDiscovered in 1818 by M. Pons, at Mar- comes their high position. seilles, it was suspected to be identical with After this specimen of eccentricity, the a comet observed in 1805, which suspicion other return comets are valuable rather as

confirmed by Encke. Regarding increasing the list of periodicals than for merely the rapidity of its successive re- any special interest they offer to the general turns, this object might be considered a reader. There is Faye's comet, with a planet; but it has been left on the list of period of seven years and a half, discovered comets, both on account of the appearances at the Paris Observatory in 1843. M. le it presents, and because it is not visible to Verrier, calculating the perturbations it us throughout the whole course of its orbit. would experience on its way, fixed its

The most noteworthy point about Encke's perihelic passage for the 3rd of April, 1851, comet results from a comparison of the a little after midnight. The prediction, dates of its successive returns to the same wonderfully exact, was fulfilled on the 2nd point of its orbit. Making every possible of April, about ten in the morning. The allowance for the disturbing forces exer- same comet was seen again in 1858 and cised on it by the planet's attraction, 1865. It ought to show itself once more Encke found that the period of its revolu- in 1873. tion is constantly diminishing, which would Brorsen's, with a period of five years and indicate the presence of a resisting medium a half, discovered at Kiel in 1846, is a more —that interstellar space is not a vacuum, slippery comet than the preceding. It was but is filled with an ether possessing some searched for in vain in 1851, but found density, however slight. Such a medium, again in 1857. Similarly, in 1862, it was by gradually checking the comet’s velocity, not forthcoming, but was detected again would cause it to yield to the sun's at- in 1868. Doubtless Astronomer Brorsen is traction; its orbit, contracting more and himself more punctual than the untrustmore, would be run through in shorter worthy vagabond who bears his name. and shorter periods of time. Encke's comet D'Arrest's comet, discovered at Leipzig was last seen in November, 1871.

in 1851, has a period of six and a half Biela's comet (with a period of six years years nearly. Its return was annonnced and three quarters) is another instance of for the end of 1857; but as it would not fantastic resemblance between the largest be visible in the earth’s northern hemiand the smallest works of the Creator. sphere, the documents, and, if we may sa There are microscopic plants and animals so, its passport, prepared by M. Yvon Vil

. (examples, closterium and trichoda) which, larceau, were sent to observatories in the after attaining a certain age, contract in southern hemisphere in anticipation of its the middle, become fiddle-shaped, hour arrival. The result answered the French glass-shaped, and finally separate into two astronomer's predictions. The comet kept independent, thrifty individuals. Micro- its appointment within twelve hours

. In scopists call this process “fissiparous mul- 1864 it gave no sign; but in 1870, on the tiplication.” But who would suppose that 31st of August, it answered to its name. a comet would ever adopt that mode of in- On the 4th of January, 1858, Mr. Tuttle crease? Nevertheless, Biela’s has, beyond discovered a comet at Cambridge, United the possibility of doubt, done so. Dis- States. Tuttle’s comet has a period of revolucovered in 1826, seen again in 1832, it could tion of something more than thirteen years not be observed in 1839 in consequence of and a half

. It was recognised at Marseilles the unfavourable position of its orbit at the by M. Borelly, in October, 1871. Finally,

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