doubtful to many minds when Napoleon led his legions from the West to perish amid the snows of Russia, and Moscow was in flames! Science has been more recently occupied with comets of short periods, insignificant in their external aspect, but deeply interesting on account of the discovery that their orbital course is included within the bounds of our system, and their predicted returns fulfilled with unfailing punctuality. The first is known as the comet of Encke. It was observed Telescopic View. in the year 1786, by Messier, traversing ments made respecting its course, incontestably establishing its character as a regular member of our system, moving in obedience to its laws. The comet appears as a small globular patch of vapour, without any starlike nucleus or tail, scarcely perceptible, and its dimness seems to be increasing. But this insignificant and shadowy thing exhibits a deeply interesting and important phenomenon, that of the gradual diminution of its periodic time, owing to a decrease in the size of its orbit, the supposed effect of a resisting medium in space, which is urging it nearer the sun, and may ultimately terminate its career as a separate body. The same conclusion is entertained with reference to the planets, founded upon this peculiarity of the comet of Encke. If the spaces in which they move is occupied by a resisting medium, that, it is conceived, will, in the long run of ages, diminish their actual velocity, decrease the centrifugal force, give more power to the solar attraction, draw them towards the centre, and thus end the system. Such a speculation is, to say the least, premature. We may admit the existence of an etherial medium which shall perceptibly affect the movements of a small vapoury globule, yet offer no appreciable opposition to the solid and weighty planetary masses. The proper course is to wait until such a medium is placed beyond all doubt, for it cannot be said yet to be demonstrated; and until we have some evidence of its action in the case of the planets, before we reason upon it as a fact. Besides the comet of Encke there is another whose periodicity has been ascertained, a discovery due to M. Biela, in 1826. This object is also without tail or nucleus, and scarcely visible to the naked eye. Its aphelion place is a little beyond the orbit of Jupiter, its perihelion within that of Venus, its time of revolution 2461 days, or 6 years. This was the comet which excited a large amount of apprehension for the safety of our terrestrial mansion, prior to its return in 1832. It was calculated that a little before midnight, on the 29th of October, it would cross the plane in which the earth revolves, near the point where our globe itself would be on the morning of the 30th of November following; and, undoubtedly, had the comet been delayed a month by any disturbance, a collision with its nebulosity would have taken place. The alarm was Jani 2037 Aphelion 1836 principally confined to the Parisians, who seem to be somewhat addicted to such fears. In the year 1773, in consequence of some rumour getting afloat concerning an expected comet, the public tranquillity was completely disturbed, and Lalande was requested by the civil authorities to interfere to assuage the popular terrors. To prevent their renewal in 1832 the authority of the Academy of Sciences was invoked in relation to the anticipated visitor, and Arago wrote a celebrated treatise to show the groundlessness of all alarm. Accordingly, the earth's progress in its orbit being at the mean rate of two millions of miles daily, and a month intervening between the passage of the comet across it and the arrival of the earth at the same point, the two bodies were never nearer than sixty millions of miles. The accompanying diagram represents its course as compared with that of the earth. On the ellipse are marked its places for the beginning of each year, from 1833 to 1840. There are 13 elliptic comets now known revolving within the orbit of Saturn; 7 whose mean distances are nearly equal to that of Uranus; and 21 of long period which pass beyond the limits of the solar system. Jan Dec.Node EARTH'S Orbit of Jupiter MajorAxis Orbits ofthe Four Small Planets Orbit of Mars ORBIT August July Venus June Line of Nodes Nov Dec Jan Feb Mar Perihelion 1833 Jand Jan1 1840 Jani 1835 Jan.1 In the spring of 1843 the world was suddenly startled by the apparition of an object in the western heavens, soon after sunset, like a streak of aurora, streaming from the region of the sun below the constellation Orion. Its outline was so distinct, and its light so conspicuous, as immediately to arrest the attention of persons abroad upon the roads, and in vessels at sea. By many observers it was mistaken at first for the zodiacal light; but its aspect and movements proved it to be a comet of the very largest class. The nucleus was not seen here, but it was visible in more southern latitudes, where the whole appearance of the comet was far more definite than with us. The phenomenon was observed on board the Tay on her homeward voyage from the West Indies, upon the 6th of March; at Nice on the 12th, by our countryman, Mr. Cooper; at Oporto on the 14th; and at Paris on the 17th. On Sunday evening, soon after seven o'clock, Mr. Cooper had his attention called by his servant to a white line of light near the western horizon. It was like a narrow thin cloud (cirro-stratus), one end being apparently merged in the remaining solar light, and the other in or near the constellation Lepus. On the 13th, at the same hour, the light re-appeared in a direction parallel to the line joining ʼn Leporis with y Eridani. On the 14th, having prepared his comet-seeker, he found the nucleus by sweeping down the line of light, which appeared stellar about the sixth magnitude. The proportion of the tail actually visible here on the nights of the 17th and 18th was fully 30° in length according to Sir John Herschel, and afterward 45° were measurable by Sir James South. Instead of being luminous at the edges, and more obscure in the middle, a general characteristic of cometary tails, which has induced the belief that they are cones internally empty, the light of the tail, in the present instance, was visibly more intense in the centre than on the sides. This was one of the largest comets ever observed, and would have appeared an extraordinary object if circumstances had been favourable to its exhibition to us. Its train must have extended through celestial space to the enormous length of a hundred and sixty millions of miles. It was travelling with prodigious velocity away from the sun, having doubled the solar orb upon first becoming visible, and soon vanished from terrestrial gaze in the immensities of the universe. In South Africa its appearance was very distinct. Mr Maclear, at the observatory in the neighbourhood of Cape Town, states:-"Of the casual observatory phenomena, the grand comet of March takes precedence; and few of its kind have been so splendid and imposing. I remember that of 1811: it was not half so brilliant as the late one. Immersed in the ravines of the Cedar-berg, with high and precipitous ranges on each side of me, I made strenuous efforts to reach the Snew-berg station, to command a view of the sudden visitor. Those unacquainted with the character of the Cedar-berg cannot form a conception of the difficulties I had to encounter. For seventeen days we toiled on, tantalised every evening by seeing a portion of the tail over the mountain tops, and sometimes a sight of its bright head, as openings in the mountains permitted." This comet, as observed at Washington, is thus described by Lieutenant Maury, in a communication from the Hydrographical Office in that city:-"On Monday morning, March 6, our attention was called to a paragraph in the newspapers, stating that a comet was visible near the sun at mid-day with the naked eye. The sky was clear; but, not being able to discover any thing with the unassisted eye, recourse was had to a telescope, without any better success. About sunset in the evening the examination was renewed with great diligence, but to no purpose. The last faint streak of day gilded the west, beautiful and delicate fleeces of cloud curtained the bed of the sun, the upper sky was studded with stars, and all hopes of seeing the comet that evening had vanished. Soon after we had retired, the officer of the watch announced the appearance of the comet in the west. The phenomenon was sublime and beautiful. The needle was greatly agitated; and a strongly marked pencil of light was streaming up from the path of the sun in an oblique direction to the southward and eastward; its edges were parallel. It was 1° 30' broad, and 30° long. Stars could be seen twinkling through it, and no doubt was at first entertained but that this was the tail of the comet. The officer of the watch was directed to search the eastern sky with the telescope in the morning, from early dawn and before, till sunrise. Nothing strange or uncommon was noted by him. Tuesday was a beautiful day. The sun was clear, gilding, as it sunk below the hills, a narrow streak of cloud, seen through the tree-tops beyond the Potomac. The tail had appeared of great length for the first time the evening before; therefore we expected to find its length this evening greatly increased. It was a moment of intense interest when the first stars began to appear. The last rays of the sun still lingered on the horizon, and at this moment a well defined pencil of hairy light was seen pointing towards the sun. At 5 h. 41 m. sidereal time, the first measurement of length of the tail was taken; it measured 41° to the horizon. At 6 h. 19 m. it had become most distinct. It was then 1° 45′ broad, and 55° long, not including the part below the horizon, which, supposing its terminus to be near the sun, could not, owing to the oblique angle which it made with the horizon, be less than 10° or 15° more. It now commenced gradually to fade away, and in a short time had entirely disappeared. The morning observations were diligently renewed, but nothing could be seen worthy of note." A letter dated March 22d from Constantinople records the advent of the visitor in that region, and the various speculations of its mongrel population concerning it :-"The attention of the public has been called from terrestrial to celestial matters within the last week, by the appearance of a luminous body in the southern hemisphere, by some declared to be a comet of extraordinary magnitude, by others a meteoric or nebulous coruscation. It becomes visible about seven o'clock, P. M., and remains in sight for about two hours. Its position is nearly S.S.W., and its magnitude, measured by the sextant, is 1o in breadth and 21° in length, with a dip of 45°. The appearance of this phenomenon has excited general interest among the natives. The mounejimbashy (chief astrologer) declares that it prognosticates great disasters to people residing southwards; it forebodes, in the first place, divers calamities to Greece; and, secondly, a termination of French Razias in Algiers. On the other hand, the Greek priests, with no other instruments than their spectacles, announce that they read in its luminous tail the restoration of the profligate Greek empire, and the downfal of modern rule in Europe. Then, again, the Persian muchats at the Valide Khan all stroke their beards, and swear by the twelve Imans that the meteor represents the flaming death-bladed sword of Ali uplifted to wreak vengeance upon the heretic followers of Omer, for the outrages recently committed upon the sainted tombs of Kerbebah. In the meanwhile, as there are neither astronomers nor instruments at this place, nothing is left for us but to await accounts from Europe, in order to determine the real nature of this extraordinary and splendid phenomenon." A European, travelling in the wilds of America, the only representative of the civilised world present upon the occasion, has graphically narrated his own impressions, and those of his Indian companions : "We were ascending the Essequibo, that noble river which, though a small rill among the mountains of the equator, disembogues its accumulated waters through three channels nearly twenty miles wide. The weather was unfavourable; torrents of rain had descended, and the sky had been covered with clouds for weeks. We were approaching the cataract Ouropocari in 4° 11′ north latitude, and had encamped, on the 8th of March, three miles below it, when, for the first time since our departure from the coast, the sky, hitherto a uniform mass of greyish clouds, cleared in the evening, and exposed, towards the south-west, the deep tropical blue, spangled with stars. We hailed with pleasure the prediction of better weather; but what was our amazement when we observed, in the W.S.W., a broad, white, nebulous band, inclining towards the horizon, and stretching to an altitude of 45°! The zenith was covered with those beautiful clouds which the meteorologist calls cirro-cumulus; the sky was, however, perfectly clear on both sides of the band which, 64′ (in arc) broad, and of a pure white, almost transparent, formed a strong contrast with the deep azure of the tropical sky. I could not observe whether the band rested apparently on the horizon, as the wall-like forest, near the edge of which we were encamped, prevented me from seeing that portion of the sky. From the point where the band became visible it appeared of a uniform breadth, becoming more transparent, and slightly diverging, near the summit. What can it be? was the first question. My Indian friends stood around, looking now with wonder at the phenomenon, now askance at me. Our doubts were solved next evening, March 9: it was a comet! Our camp was so favourably situated that the south-western horizon was exposed to our view. The sky was partially clouded until seven o'clock, when the clouds to the west cleared away, and there stood the comet in all its grandeur, the nucleus being about 12° above the horizon, and the tail extending to the star v Eridani, then about 45° high. The nucleus appeared, to the naked eye, like a star of the second magnitude; its tail, near the base like a narrow band, spread in its broadest part 1° 10′, and lost itself in the constellation Eridanus. The whitish light and transparent vapour of its tail, resembling more those clouds compared to 'The beauteous semblance of a flock at rest,' diverged about 20° below the foot of Orion, in nebulous stripes. We stood amazed. A bright moon somewhat lessened the effect which this most wonderful of all natural phenomena would have produced had all else been hidden in darkness; but the extent of the tail rendered it remarkable; indeed, it was the largest which we, who stood assembled, had ever witnessed in our lifetime. I still recollect the beautiful comet of 1811, with its diverging beams of fiery hue, but its tail was much less in length than the one now looked upon. It was a scene which has fixed itself firmly upon my memory. There we stood, upon a small island in the middle of the Essequibo, surrounded by foaming waters which, opposed in their course by dykes of granite, went thundering away over the black stony masses,- -I the only European among a number of naked savages, the coppery tint of whose bodies shone in strong contrast when the burning embers of the camp fires threw a ray upon their figures; some standing upright, with their arms across their breast, others squatting on the ground, but their fearful eyes all directed towards the strange star with its luminous train. No word was spoken. The rush of the foaming waters was the only interruption of the silence. Tamanua, a young Wapisiana, of more intelligence than is generally met with among his tribe, at last broke silence: This is the Spirit of the stars, the dreadful Capishi-famine and pestilence await us;' and, as if they had only wanted the utterance of a syllable to give vent to their feelings, the assembled Indians burst into a torrent of declamation, lamenting the appearance of the dreaded Capishi, as the precursor of pestilence and famine, and raising, with violent gesticulations, their arms towards the comet. I was surprised to find among my Indian followers the same superstitious dread of a comet which, in all ages, rendered their celestial appearance the terror of the uninstructed and vulgar. The Indians around me consisted of Arécuna; Wapisianas, and Macusis. The first called the comet Wátaimá, signifying, like Capishi, the Spirit of the stars. The Macusi Indians named it Cá-poéséimá, a fiery cloud,' or Woe-inopsa, 'a sun casting its light behind.' Must we not acknowledge that these simple children of Nature have given to this magnificent phenomenon a more expressive name than we civilised nations?" This comet is remarkable on various accounts. It advanced nearer to the solar surface than any other on record. That of 1680 approached the sun within one-third of his diameter; but that of 1843 came within one-seventh, and was consequently more than |