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PART II.

COMET-SEEKERS.

“Wherefore if it should return according to our prediction, about the year 1758, impartial posterity will not refuse to acknowledge that this was first discovered by an Englishman.”-Halley's words concerning the return of his comet.

Who has not heard of Halley's comet, a blazing traveller of the sky, first discovered by an Englishman ? Halley traced his comet back to the year 1531 ; then on to 1607, and down to his own time; others have traced back the shining traveller of unknown age till they arrive at the year 989, A.D. We read of it as having been seen from the Icelandic shores, where it “exhibited a great and extensive tail, stretched across a considerable part of the heavens.” The French historians mention it in 1223, as a “wonderful sign in the heavens, which appeared just before the death of their king, Philip Augustus ; and previously we read of it in English history as the terrible comet of the Norman Conquest. Again and again the bright vision flashes upon us, as we travel through the pages of history, till we come to regard it as an ancient friend. And so with many other comets.

Edmund Halley was born at Haggerston, near London, in 1656; he studied at S. Paul's School, and afterwards at Oxford University, where he excelled in mathematics, by means of which he was able with the help of his telescope to become learned in astronomy. After careful study of the sun, he discovered a spot on the dazzling disc, a spot he had not seen before ; this was of more importance than might first appear; for by observing this spot it was made possible to find out much concerning the way in which the sun rotates on its axis ; on this subject Halley, at the age of twenty, published papers of great value to astonomers.

While yet very young, Halley became so celebrated for what he had written, and for the good work he had done in astronomy, that he was sent out to the island of S. Helena by the recommendation of the king (Charles II.,) who had been told that the clever youth from Oxford, who had written of the sun's movement on its axis, and who had done work concerning Mars and the moon, by the help of which he and others had settled the longitude of the Cape of Good Hope, had a great desire to travel to S. Helena, that he might observe those stars “ which lie so near the south pole, that they could not be observed by

astronomers living in northern latitudes ;” these stars “never rising above the horizon either at Dantzic or at Greenwich.”

In Halley's time the astronomer Hevelius was living at Dantzic, he is much remembered in connection with the transit of Mercury. Now it was well known that while Hevelius was working at Dantzic our astronomer, Flamstead, was working at the Observatory, Greenwich, and they were both making a list of all the stars they could see.

Edmund Halley was glad enough when he found himself on his way to the island of S. Helena, from whence he hoped to see many stars he had never beheld before. Think then what must have been his disappointment on his arrival, at finding that lovely island so often veiled in mist and fog, that he could very seldom see clearly the stars for the sake of which he had crossed the ocean.

Halley was not one to give way to despair ; he did what he could by seizing the telescope whenever there was a clear starlight night ; and by this watchful industry he succeeded in ascertaining the positions of as many as three hundred and fifty stars. Of these he made a catalogue, which he published with an account of the way in which he had worked.

On his return to England, when he was about twenty-eight years of age, the king continued to show him favour, which helped him to gain many things he wished : it was not long, however, that he required royal, or other assistance; his own talents and industry were sufficient in themselves. About two years after his arrival in England, he was sent by the Royal Society of which he was now elected a member, to Dantzic on astronomical business, and on the death of Sir Hans Sloane, he was appointed Secretary to the Royal Society : this was in 1685.

Halley now received honour upon honour : he was requested by the Royal Society to edit Newton's Principia, at the beginning of which work he wrote some Latin verses. On the death of Dr. Wallis, Halley was chosen as his successor to the chair of Savilian Professor of Geometry at Oxford. In 1720, after the death of Flamstead, the astronomer royal, Halley was appointed to succeed him, and he took up his abode at the Observatory, Greenwich.

After accomplishing many difficult and honourable tasks in the service of astronomy, the warning came : bis activity was checked by a stroke of paralysis; he lingered on until January, 1742, when he passed away without a groan.

It was in 1682 that Halley saw the comet named after him, which is one of especial interest, as being the first the periodic time of which was ascertained with certainty. Having seen the comet, Halley, as it were, made it his own; he observed its position most carefully; he reckoned the orbits of other comets to be read of in history; he compared all these together; and after many hours of solitude and thought he told the world, in 1682, that this comet would come again within sight of the earth in the year 1758—9.

And the comet came as he had predicted ; but Halley had passed away seventeen years before, and lay at rest in Lee churchyard, near Blackheath.

This comet appeared again after another journey of seventy-five years; namely in 1835.

Halley’s comet-was seen again and again many centuries before its length of journey was fixed and its name received : it has always visited us every seventy-five years ; but before the time of Halley, its visits were each time a matter of surprise. Astronomers and others have searched history, carefully looking out for Halley's comet, and they have found as many as twenty-three mentions of one which appeared at the time when Halley's might have been expected to shine forth in the skies of our solar system : it seems that the history of this comet may be traced back as far as the year 130 B.C., when it is said to have lingered within sight of the inhabitants of the earth for twentyfour days; the ancient historians tell us it was brighter than the sun;" doubtless the terror of our forefathers caused them to think it brighter than it was. We find in history several mentions of this comet afterwards, appearing as it did every seventy-five years, but often either unseen or unrecorded. At one time we read of it as a dazzling wonder of “monstrous size and terrible aspect, its tail seeming to reach to the ground;" at another time it is a flaming object, having "an immense curved tail in the form of a scythe, and a head four times as large as the planet Venus.” Then again we hear of it,and this is in the reign of our Edward I., -as “a great and fearful star;" and later on it is of “unheard magnitude, its fiery tail sweeping over the whole length of the heavens.” Thus we meet with the comet time after time till we feel familiar with it by the time Halley took it in hand in 1682, when it was about to make its twenty-fourth appearance, and to receive a name and a calculated place in the movements of the solar system.

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Astronomers bave made us acquainted with the times and movements of other comets besides that of Halley. There is Encke's comet, a small one not to be seen without the telescope; it appears every

three years and a half, revolving between Jupiter and Mercury. This small comet is slowly approaching the sun, its orbit very gradually becoming smaller until it may be swallowed up in the flames of our great central light; on the other hand, astronomers have said it may, as soon as it approaches very near the sun, begin to retreat and enlarge its orbit again. The comet is named after Encke, an astronomer of Berlin, who in 1819 fixed its times of appearance by his careful calculations. Biela's comet is named after an Austrian officer, who discovered it in 1826. This small comet appears every six years and a half, and passes very near to the earth. In the year 1846 it was seen to separate into two.

There is one comet which seems to have received no other name than "the comet of 1843.” This is a large and extremely beautiful one. Astronomers tell us its luminous tail is two hundred millions of miles long; thus, as we read in the “Heavens and the Earth,” by Thomas Miller, F.R.S., (page 277,)“ had it been coiled around the earth like a serpent, it would have girdled it eight thousand times at the equator."

Donati's comet appeared only twenty-three years ago. Many of our readers may remember how bright and large it was as it shone forth from evening to evening in the lovely summer of 1858; it is named from Dr. Donati, of Florence, by whom it was discovered on the 2nd of June, 1858. It is said by astronomers that the inhabitants of the earth will not see it again till nearly another two thousand years.

G. B. Donati was born at Pisa in Italy in 1826. When he was only twenty he was appointed to do important work at the observatory in the beautiful city of Florence. He worked so well that he was

1 Johann Franz Encke was born at Hamburg in Germany (1791.) Like all Germans, he was in readiness to fight whenever the ghastly news of war was heard. He fought for his country in 1813. As soon as peace was proclaimed, he returned to the happy occupations of peace, which in his case was the study of the heavens, and he obtained such an appointment as delighted him,-he was made assistant at the observatory of Seeberg, near Gotha. In 1825, when about thirty-five years of age, he found himself director of the Berlin Observatory. And now it was that he began to be known as a diligent observer of comets, directing his attention particularly to that comet which is now known by his name. Encke died on September 2, 1865, aged sixty-one.

? And independently, on the 29th of the same month, by Parkhurst, at Perth, Amboy, New Jersey, U. S.

noticed by astronomers as one worthy of advancement. Before long, his name was known in other countries as a man of science. In 1858 all the world was talking of the Italian astronomer, Donati, who had made discoveries concerning the magnificent comet since named after him. He did other work unconnected with the comet in connection with the spectroscope.

When Donati came to be about forty-two years of age, he was made director of the observatory in which he had diligently worked for twelve years. His thoughts now turned to the hill at Arcetri, where died one whom all astronomers remember with love and reverence. He thought of the place where Galileo had spent his last days, and being now in a position of power, undertook to build a new observatory on that sunny hill. Donati began the work, and it was going on well, when his plans were suddenly cut short by death. In 1873 he went to Vienna to attend an assembly of scientific men; he safely returned home, but was shortly afterwards struck down by an illness which carried him off. It was at his own house at Arcetri that Donati died, on September 20, 1873, aged forty-seven.

Of the comet which is still brightly shining while we write, it would be superfluous to speak, as the papers of the day are full of conjectures and information concerning this shining stranger.

M. G. M.

CONTRASTS.

BY THE AUTHOR OF

A LEGEND OF RHOSBERRY TOPPING."

CHAPTER 1.

THE July sun was blazing on the open space at the back of the Great Western Station at Oxford. The cab horses were standing wearily with drooping heads, slowly switching away the flies with their tails. Dust and heat seemed to pervade everything. One person however, seemingly unconscious of them, stood out in the full sunshine in the middle of the road, shading his eyes with his hand and gazing intently towards the town. He was a tall loosely built youth of the regular English type, with merry blue eyes, and a face beaming with hearty good-natured fun. His clothes showed signs of wear and tear, and certainly had never known the inside of a London tailor's shop.

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