the morning twilight, or that faint light which appears in the morning when the sun is within 18 degrees of the horizon.

goddess of the morning, according to the Pagan mythology. She was the daughter of Hyperion and Theia, according to Hesiod; but of Titan and Terra, according to others. It was under this name that the ancients denoted the light which foretells the rising of the sun above our hemisphere. The poets represent her as rising out of the ocean, in a chariot, with rosy fingers dropping gentle dew. Virgil describes her ascending in a flame-coloured chariot with four horses.

of the New Hebrides islands in the South sea, in which Mr Forster supposes the Peak d'Etoile mentioned by Mr Bougainville to be situated. The island is inhabited; but none of its inhabitants came off to visit Captain Cook. The country is woody, and the vegetation seems to be excessively luxuriant. It is about 12 leagues long, but not above five miles broad in any part; lying nearly north and south. The middle lies in S. Lat. 15. 6. E. Long. 168. 24.

Aurora Borealis, Northern Twilight, or Streamers; a kind of meteor appearing in the northern part of the heavens, mostly in the winter-time, and in frosty weather. It is now so generally known, that no description is requisite of the appearance which it usually makes in this country. But it is in the arctic regions that it appears in perfection, particularly during the solstice. In the Shetland islands, the merry dancers, as they are there called, are the constant attendants of clear evenings, and prove great reliefs amidst the gloom of the long winter nights. They commonly appear at twilight near the horizon, of a dun colour, approaching to yellow; sometimes continuing in that state for several hours without any sensible motion; after which they break out into streams of stronger light, spreading into columns, and altering slowly into ten thousand different shapes, varying their colours from all the tints of yellow to the obscurest ruddiness. They often cover the whole hemisphere, and then make the most brilliant appearance. Their motions at these times are most amazingly quick; and they astonish the spectator with the rapid change of their form. They break out in places where none were seen before (skimming briskly along the heavens) are suddenly extinguished, and leave behind an uniform dusky tract. This again is brilliantly illuminated in the same manner, and as suddenly left a dull blank.

In certain nights they assume the appearance of vast columns, on one side of the deepest yellow, on the other declining away till it becomes undistinguishable from the sky. They have generally a strong tremulous motion from end to end, which continues till the whole vanishes. In a word, we, who only see the extremities of these northern phenomena, have but a faint idea of their splendour and their motions. According to the state of the atmosphere, they differ in colours. They often put on the colour of blood, and make a most dreadful appearance. The ruddy tinges become prophetic, and terrify the gazing spectators with the dread of war, pestilence, and famine. This superstition was not peculiar to the northern islands; nor are these appearances of recent date. The ancients called them Chasmata, and Trabes, and Bolides, according to their forms or colours.

In old times they were extremely rare, and on that account were the more taken notice of. From the days of Plutarch to those of our sage historian Sir Richard Baker, they were supposed to have been portentous of great events, and timid imagination flamed them into aerial conflicts:

Fierce fiery warriors fight upon the clouds In ranks and squadrons and right form of war.

Dr Halley tells us, that when he saw a great aurora borealis in 1716, he had begun to despair of ever seeing one at all; none having appeared, at least in any considerable degree, from the time he was born till then. Notwithstanding this long interval, however, it seems that in some periods the aurora borealis had been seen much more frequently; and perhaps this, as well as other natural phenomena, may have some stated times of returning.

The only thing that resembles a distinct history of this phenomenon, is what we have from the learned Dr Halley, Phil. Trans. No. 347. The first account he gives, is of the appearance of what is called by the author burning spears, and was seen at London on January 30th, 1560. This account is taken from a book entitled, A Description of Meteors, by W. F. D. D., and reprinted at London in 1654. The next appearance, on the testimony of Stow, was on October 7th, 1564. In 1574 also, according to Camden, and Stow above-mentioned, an aurora borealis was observed two nights successively, viz. on the 14th and 15th of November, with much the same appearances as described by Dr Halley in 1716, and which we now so frequently observe. Again, the same was twice seen in Brabant, in the year 1575; viz. on the 13th of February and 28th of September. Its appearances at both these times were described by Cornelius Gemma, professor of medicine in the university of Louvain, who compares them to spears, fortified cities, and armies fighting in the air. After this, Michael Maestlin, tutor to the great Kepler, assures us, that at Bakenang in the county of Wurttemberg in Germany, these phenomena, which he styles chasmata, were seen by himself no less than seven times in 1580. In 1581, they again appeared in an extraordinary manner in April and September, and in a less degree at some other times of the same year. In 1621, September 2d, this phenomenon was observed all over France, France, and described by Gassendus, who gave it the name of aurora borealis: yet neither this, nor any similar appearances posterior to 1574, are described by English writers till the year 1707; which, as Dr Halley observes, shows the prodigious neglect of curious matters which at that time prevailed. From 1621 to 1707, indeed, there is no mention made of an aurora borealis being seen by any body; and considering the number of astronomers who during that period were in a manner continually poring on the heavens, we may very reasonably conclude that no such thing did make its appearance till after an interval of 86 years. In 1707, a small one was seen in November; and during that year and the next, the same appearances were repeated five times. The next on record is that mentioned by Dr Halley in March 1715—16, the brilliancy of which attracted universal attention, and by the vulgar was considered as marking the introduction of a foreign race of princes. Since that time those meteors have been so common, that no accounts have been kept of them.

It was for a long time a matter of doubt whether this meteor made its appearance only in the northern hemisphere, or whether it was also to be observed near the south pole. This is now ascertained by Mr Foster; who in his late voyage round the world along with Captain Cook, affirms us, that he observed them in the high southern latitudes, though with phenomena somewhat different from those which are seen here. On Feb. 17, 1773, as they were in Lat. 58° south, "A beautiful phenomenon (says he) was observed during the preceding night, which appeared again this and several following nights. It consisted of long columns of a clear white light, shooting up from the horizon to the eastward, almost to the zenith, and gradually spreading on the whole southern part of the sky. These columns were sometimes bent sidewise at their upper extremities; and though in most respects similar to the northern lights (aurora borealis) of our hemisphere, yet differed from them in being always of a whitish colour, whereas ours affume various tints, especially those of a fiery and purple hue. The sky was generally clear when they appeared, and the air sharp and cold, the thermometer standing at the freezing point."

Dr Halley observed that the aurora borealis described by him arose to a prodigious height, it being seen from the west of Ireland to the confines of Russia and Poland on the east; nor did he know how much further it might have been visible; so that it extended at least 30 degrees in longitude, and from Lat. 50° north it was seen over all the northern part of Europe; and what was very surprising, in all those places where it was visible, the same appearances were exhibited which Dr Halley observed at London. He observes, with seeming regret, that he could by no means determine its height, for want of observations made at different places; otherwise he might as easily have calculated the height of this aurora borealis, as he did of the fiery globe in 1719*. To other philosophers, however, he gives the following exhortation. "When therefore for the future any such thing shall happen, all those that are curious in astronomical matters are hereby admonished and entreated to let their clocks to the apparent time at London, for example, by allowing for many minutes as is the difference of meridians; and then to note, at the end of every half hour precisely, the exact situation of what at that time appears remarkable in the sky; and particularly the azimuths of those very tall pyramids so eminent above the rest, and therefore likely to be seen furthest: to the intent that, by comparing these observations taken at the same moment in distant places, the difference of their azimuths may serve to determine how far these pyramids are distant from us." This advice of Dr Halley seems to have been totally neglected by all the philosophical people in his country. In other countries, however, they have been more industrious. Father Boscovich has determined the height of an aurora borealis, observed on the 16th of December 1737 by the marquis of Poletti, to have been 825 miles high; the celebrated Mr Bergman, from a mean of 30 computations, makes the average height of the aurora borealis to be 70 Swedish, or upwards of 450 English miles. Euler supposes it to be several thousands of miles high; and Mairet also affirms them a very elevated region. In the 7th volume of the Philosophical Transactions, Dr Blagden, when speaking of the height of some fiery meteors, tells us, that the "aurora borealis appears to occupy as high, if not a higher region above the surface of the earth, as may be judged from the very distant countries to which it has been visible at the same time." The height of these meteors, however, none of which appear to have exceeded or even arrived at the height of a hundred miles, must appear trifling in comparison of the vast elevations above mentioned. But these enormous heights, varying so exceedingly, show that the calculators have not had proper data to proceed upon; and indeed the immense extent of space occupied by the aurora borealis itself, with its constant motion, must make it infinitely more difficult to determine the height of it than of a fiery globe, which occupies but a small portion of the visible heavens. The most certain method of making a comparison between the aurora borealis and the meteors already mentioned, would be, if a ball of fire should happen to pass through the same part of the heavens where an aurora borealis was; when the comparative height of both could easily be ascertained. One instance of this only has come under our observation, where one of the small meteors, called falling stars, was evidently obscured by an aurora borealis; and therefore must have been higher than the lower part of the latter at least. A singularity in this meteor was, that it did not proceed in a straight line through the heavens, as is usual with falling stars, but described a very considerable arch of a circle, rising in the north-west, and proceeding southward a considerable way in the arch of a circle, and disappearing in the north. Its edges were ill defined, and five or six coruscations seemed to issue from it like the rays painted as issuing from stars. The aurora borealis was not in motion, but had degenerated into a crepuscule in the northern part of the hemisphere. Indeed, in some cases this kind of crepuscule appears so plainly to be connected with the clouds, that we can scarcely avoid supposing it to proceed from them. We cannot, however, argue from this to the height of the aurora borealis when it moves with great velocity, because it then may, and very probably does, ascend much higher. Dr Blagden, in