It is evident that these artistic efforts are not true to nature, however true to such wild and distorted descriptions as the following, from the " Exempla Cometarum" of Rossenburg, a contemporary of Newton :- "In the year 1527, about four in the morning, not only in the Palatine of the Rhine, but nearly over all Europe, appeared for an hour and a quarter a most horrible comet, in this sort. In its length it was of a bloody colour, inclining to saffron. From the top of its train appeared a bended arm, in the hand whereof was a huge sword in the instant posture of striking. At the point of the sword was a star. From the star proceeded dusky rays, like javelins or lesser swords, as if imbrued in blood, between which appeared human faces of the colour of blackish clouds, with rough hair and beards. All these moved with such terrible sparkling and brightness, that many spectators swooned with fear!"

Before we finally take leave of the comet of Halley, some notice may be bestowed upon his claim to the distinction of being the first to foretell the precise periodical return of one of these bodies. This has been disputed, and assigned to Newton, on evidence recently detailed in one of the leading journals, but which certainly cannot be admitted to invalidate his pretensions. It is affirmed that previously to the appearance of the comet of 1736, Colonel Guise told Whiston that Sir Isaac Newton had said in his presence, that "though he would not say he was sure of it, nor would publish it, he had some reason to believe that a comet would return about the latter end of 1736." Another witness also, Mr. Howard, is cited, as having heard him make a similar remark; and upon being questioned concerning it, it is stated that "he seemed to draw back, as sorry that he had said so much, but still could not deny that he had such an expectation." Whiston therefore says:-"As far as we yet know, Sir Isaac is the very first man, and this the very first instance, where the coming of a comet has been predicted beforehand, and has actually come according to that prediction, from the beginning of the creation to this day." Thomson seems to fall in with this idea in panegyrising the great philosopher :

"He, first of men, with awful wing pursued
The comet, through the long elliptic curve,
As 'long innumerous worlds he wound his way,
Till to the forehead of our evening sky
Return'd, the blazing wonder glares anew,
And o'er the trembling nations shakes dismay."

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This is all the evidence that can be arrayed in favour of Newton; and obviously its hearsay source, with the dubious tone of the testimony reported, cannot weigh a feather in the scale against the claims of Halley, whose prediction was the result of careful comparison, and as such boldly published to the world.

The next most remarkable comet of modern times appeared about the middle of December, 1743, and continued visible during the spring of the year following. On the 1st of February, according to Chizeaux, it was more brilliant than. Sirius, the brightest star in the heavens. On the 8th it equalled Jupiter, and was visible in the presence of the sun at the beginning of the next month. By selecting a convenient situation many persons saw it at mid-day without glasses. Several instances of similar brilliancy are on record. Justin mentions a comet which appeared at the birth of Mithridates, and overcame the brightness of the sun by its splendour; and, however this may be an exaggeration, there are many well-attested cases of these bodies being seen by broad daylight. The Cæsarian comet, two others in 1402, with one in 1532, were thus visible. The fine comet of 1577 was seen with the naked eye by Tycho Brahe before sunset. On account of its brightness and peculiar form the comet of 1744 excited great attention and interest. It exhibited no train until within the distance of

the orbit of Mars from the sun; but, early in March, it appeared with a tail divided into six branches, all diverging, but curved in the same direction. Each of these tails was

about 4° in width, and from 30° to 44° in length. The edges were bright and decided, the middle faint, and the intervening spaces as sombre as the rest of the firmament, the stars shining in them. This comet was repeatedly seen in Switzerland, with the nucleus below the horizon, and the six tails extending from twenty to thirty degrees above it. The scene presented by this remarkable body in the situation referred to was striking in the extreme when circumstances favoured the display.

In the year 1770 a comet appeared which has acquired considerable notoriety from the alterations which its orbit has undergone. It was first observed by Messier, a man who united great simplicity of character with high scientific attainments. Louis XV. called him le furet des cométes, from his zeal in hunting after them. He had discovered twelve, every one of which, says Delambre, gained him admission to some foreign academy. While attending to his wife during her last moments, Montagne discovered another. This was a cutting stroke to Messier, and he exclaimed, "Alas, I had discovered twelve, and this Montagne has taken away my thirteenth!" Then remembering that it was his wife he should mourn for, he began to say, "ah! la pauvre femme!" and went on deploring his comet. The elements of the comet of 1770 were calculated by Lexel, who found for its orbit round the sun an ellipse of which the transverse diameter was only equal to three times the diameter of the earth's orbit, which corresponded with a period of revolution of five years and a half. It was deemed a singular circumstance that an object having so short a periodic time, whose greatest distance from the sun was not far beyond the orbit of Jupiter, and which shone with a vivid light, should not have been observed before; and the wits of the day made themselves merry, when, at the expiration of the appointed term, the comet was not observed to return. It has not been seen since; and was popularly called Lexel's lost comet. But this sport was premature. The previous

invisibility and subsequent disappearance of this body, after once presenting itself, have been sufficiently explained; and a confirmation of the laws of universal attraction has been drawn from circumstances apparently adverse to them. Its previous invisibility is accounted for by its orbit being altogether different prior to the year 1770, its nearest point to the sun being as distant as the path of Jupiter, corresponding, not to five, but to fifty years of revolution. Its appearance that year arose out of the fact that in 1767 it was in such close contact with the planet, moving in the same direction and in nearly the same plane, that the attraction of the sun upon it was not that of Jupiter. This entirely altered the form of the orbit, and caused the comet to wheel its path towards that of the earth, coming within our view, and executing the ellipse described by Lexel in the periodic time of five and a half years. But why has not the comet since been seen? Its passage to the point of perihelion in 1776 took place by day; and in 1779, before another return, it again encountered the vast body of Jupiter, and suffered a fresh orbital derangement, the attraction of the planet deflecting it into more distant regions. The comet therefore, though "lost" to us, is in existence, and in each instance of its change of route has faithfully obeyed the laws of gravitation. Those laws in 1770 introduced it as a bright and beautiful stranger to the notice of the human race, and again in 1779 stopped the fellowship, removing the comet into a remoter path, where it is hid from the gaze of man, and will be so unless some new perturbation directs its course towards the terrestrial orbit. Another comet, exhibiting some remarkable features, presented itself in the year 1807. It was assiduously observed by Herschel in this country, and by the continental astronomers, Schroeter, Bessel, and Olbers. The drawings of the two former are here given,

taken on two succeeding evenings, which show a divided tail, the separate branches having varied their aspects. Coruscations, flickering and vanishing like the northern lights, appeared to shoot out in an instant from the train to an immense extent.

In the autumn of 1811, within the memory of many of the present generation, by far the finest comet suddenly appeared to adorn our heavens, that had been seen since the age of Newton. It was first beheld in this country in the beginning of September, and was visible for more than three months in succession to the naked eye, shining with great splendour, the observed of all observers. This was a comet of the first class in point of magnitude and luminosity. Its brilliant tail, at its greatest elongation, had an extent of 123 millions of miles, by a breadth of 15 millions; and thus, supposing the nucleus of the comet to have been placed on the sun, and the tail in the plane of the orbits of the planets, it would have reached over those of Mercury, Venus, the Earth,

and have bordered on that of Mars. At its nearest approach to us, the comet was yet distant 141 millions of miles, so that even had the tail pointed to the earth, its extremity

would have been 18 millions of miles away from its surface. The following are the calculations respecting its period of revolution:

Years.

Authority.

The mind is astounded at a journey requiring the least of these cycles for its accomplishment a period equal to that extending from the fabulous age of Grecian story to the present; nor is the thought less wonderful, of the chain of solar influence following the traveller through the whole of its course, and preventing its elopement into the regions of immensity. The laws of the system, indeed, impose upon the long-period comets vast differences of velocity. The same body that rushes round the sun at the nearest point of contact with prodigious speed, will move but sluggishly through the remoter parts of its orbit. In computing the periodic time of the comet of 1811, Lemaur assigned 775 years to the half of the ellipse nearest the sun, and 3462 to the more distant half. But the space must be immense that has to be traversed by an object whose return is not expected, taking the lowest estimate given, till the year 4867. The appearance of this comet was strikingly ornamental to the evening sky. Many a reaper late in the harvest field stayed his hand, and many a peasant homeward-bound stopped in the way, to gaze upon the celestial novelty as it grew into distinctness with the declining day. The Ettrick shepherd has left a memorial of his impressions in the well-known lines :

Those who were alive in 1811 will recollect the high temperature of that year—its bountiful harvest-its abundant vintage. Popular opinion assigned these blessings to the resplendent comet; and the wine of the comet was sold afterwards at high prices. No doubt, however, but that precisely different circumstances would have been connected,

a cold

by the public mind, with the same cause; and this has literally been the case, for " winter," and "meteors in Germany," are referred to the comet of 1680, by a writer in 1829. The following table, given by Arago, is valuable upon this point:

From this table, it is clear that no conclusion can be drawn, to the effect that cometary appearances have any influence in raising the temperature. In 1828 and in 1831 no comets presented themselves, and the temperature was nearly at its maximum. In 1808 there were four, and it was nearly at its minimum.

There was no inconsiderable amount of superstitious fear blended upon this occasion with the natural feelings of wonder and admiration that were excited. As the great comet of 1680 had been deemed a manifest presage of the revocation of the edict of Nantes, the persecution of the French protestants, and the long wars that ensued, so was the beautiful

and transient visitor of 1811 abused in a similar manner. It was widely regarded as the herald of some awful terrestrial occurrence, and the particular event intended was not