appeared in the years 1155, 1230, 1305, 1380, 1456,1531,1607 and 1682, between each of which dates a period of seventyfive or seventy-six years intervenes. The year 1758 approached, and the French astronomers, Lalande and Clairaut, assisted by Madame Lalande, began to reconsider its elements, and asserted that it would be later in appearing than was expected, owing to the attraction of Jupiter and Saturn, which the comet would have to pass. The whole of Europe was on the alert; and on Christmasday, 1758, the anticipations of Halley and the French astronomers, were realized by the discovery of the comet. It passed its perihelion, the point of its orbit nearest the sun, on the 12th of March, 1759, exactly within the limits determined by the French astronomers. According to subsequent announcements the comet appeared again in 1835, and passed its perihelion in November of that year; on each occasion proving, by its peaceful passage, and quiet, though swift departure, that the lines A pathless comet, and a curse, The menace of the universe; Still rolling on with innate force, Without a sphere, without a course: are too fictitious even for the license of poetry—these bodies being as subject to law as the other bodies of the system, and so far from "Menacing," courting and engaging intellectual enquiry. One of the most wonderful comets of modern times was that of 1743, which had six tails, all curved in the same direction, and diverging from its body. It first appeared in December, 1743, and continued visible during the spring following. On the 1st of February it was more brilliant than the star Sirius; on the 8th it rivalled Jupiter; and was visible even when the sun shone at the beginning of the next month. By selecting suitable places, many persons saw it at mid-day without glasses. Its six separate tails spread out like a fiery fan, and each measuring from thirty to forty degrees in length, and four in width; the edges were bright and sharp, the middle faint, and the intervening spaces as sombre as the rest of the firmament the stars shining through them. This comet was frequently seen in Switzerland, with the nucleus far below the horison, and the six tails extending twenty or thirty degrees above it. On the whole it was one of the most striking exhibitions on record. In 1811 the finest comet which the present generation have yet seen appeared. It was beheld in this country in the beginning of September, and was visible for more than three months to the naked eye, shining with great splendour, the observed of all observers. It was a comet of first class, and had a tail of 123,000,000 miles in length, by 15,000,000 in breadth. Supposing the body of the comet to have been placed on the sun, its tail would have extended sufficiently far to pass Mercury, Venus and the earth, and to approach the neighbourhood of Mars. It came no nearer to us than 141,000,000 of miles, so that if its tail had been pointed towards the earth, it would not have touched it by 18,000,000 of miles. Various estimates have been formed as to the period of its revolution, and periods ranging from three thousand and fifty-six to four thousand two hundred and thirty seven years assigned it. Even the last of these periodsconstituting only one year of the comet's history-overwhelms us with its magnitude, and carries back the mind to the infant state of man when cities were unfounded, and fable was lisped from the lips of men then in the first dawn of civilization. Yet in this journey of three thousand and fifty-six years in COMET OF 1811. many a peasant homeward bound stopped in his way, to gaze upon the celestial novelty as it grew into distinctness with the declining day," the "Ettric Shepherd" has left some lines descriptive of the impression made on his mind by this mysterious visitor. How lovely is this wilder'd scene, As twilight from her vaults so blue, All hail, ye hills, whose towering height, Stranger of heaven! I bid thee hail! Broad pennon of the King of heaven! Art thou the flag of woe and death, No, from that pure pellucid beam, That erst o'er plains of Bethlehem shone,* Bright herald of the eternal throne! Whate'er portends thy front of fire, Thy streaming locks so lovely pale,- Stranger of heaven, I bid thee, hail! The year 1811 was marked by hot weather, an abundant harvest, and a fruitful vintage. Popular opinion assigned these gifts to the influence of the comet; and the wine produced that year was sold at very high prices. That it was fallacious to attribute such influences to the comet, there can be little doubt, for "a cold winter" and meteors in Germany are re ferred to the comet of 1680 by a writer in 1829. The visitor of 1811 was terribly abused. Just as that of 1680 had attributed to it the revocation of the edict of Nantes, and the persecution of the French Protestants, and the long war that ensued; so this latter visitant was widely regarded as the herald of some ENCKE'S COMET. terrible convulsions, not a few seeing its effects amid the marching of Napoleon's armies of the West, to perish in * It was reckoned by many that this was the same comet which appeared at the birth of our Saviour. the Russian snows, and the awful conflagration which consumed the city of Moscow. Encke's comet was first observed by Messier in 1786, afterwards seen by Miss Herschel in 1795, and again by M. Pous in 1805, affords a good instance of the periodical movements which comets perform in common with other celestial bodies, and sufficiently demonstrates the absurdity of the line-"Without a sphere, without a course." This comet appeared in 1819, and was shown by Encke to be identical with the previous appearances just mentioned; and having established the identity, the comet received his name. When nearest the sun it is within the orbit of Mercury, and when farthest between the planetoids and Jupiter, so that it is an integral part of the planetary system, and performs all its motions in close vicinage to the planets. Its revolution is performed in twelve hundred and three days, or three and three-tenths years. None of the comets have been more true to their appointments than this, which has established itself as a regular constituent of our system. It has however obtained an interest of its own from certain conditions of space which its motions indicate; and in this respect it is perhaps the most instructive comet yet seen. It has been found that by watching Encke's comet, and noting the several passages it has made, that it approaches at every fresh revolution, nearer and nearer to the sun. A mode of explaining this progressive approach to the solar body, is to suppose the existence of a medium in space able to resist its motions, and allows the sun to gain upon it gradually by the force of attraction. This explanation has been regarded by scientific men as so satisfactory, that it is universally adopted; and it is now a part of the astronomical faith, that space is filled with a thin ether which resists the motions of the various bodies, and to a slight extent retards their progress. The conjectures which follow upon this admission are many and important. Will the planets be arrested by this pervading ether, and driven nearer and nearer to the sun, until at last they verge into the solar body, as the comets themselves appear to be doing? or is there some compensating power, which |