by the alteration produced in the distance of the visible horizon. A ship, the Henrietta of Whitby, bearing easterly from us, lay beset at such a distance, that her hull was not visible; and when viewed from an elevation of ninety feet, with a good telescope, half her lower masts were intercepted by the ice on the horizon. Now at the elevation from which this ship was seen, the horizon, under common circumstances, would be nine miles distant; and from the knowledge of the dimensions of her masts, I estimated the portion of the hull and masts intercepted by the horizor, at about 22 feet; consequently, her distance beyond the horizon must have been at least 4 miles, and her distance from us not less than 13.

"The day had been almost cloudless, the sun powerful. At 11 p.m., I was informed by the officer of the watch, that the ship to the eastward of us, appeared to be forced by the ice upon her beam ends, or into an heeling posture. I immediately ascended the deck, and having cleaned the glasses of a good telescope, I hastened to the mast-head. I at once attributed the cause of the deception to unequal refraction. This ship, which, two hours before, was 43 miles beyond the visible horizon, now appeared as far within it, and was in every respect deformed like the ships above mentioned. The ice between us and the Henrietta was compact and motionless; in confirmation of which, a few hours afterwards, we found she had resumed her former appearance; that is, she had apparently returned to her situation beyond the horizon. Now, the distance of the Henrietta, 13 miles, as before determined, added to about 4 miles that the horizon was visible beyond her, gives 17 miles for its distance, which is greater by 8 miles, than we derive from estimation, on the principle of the earth's curvature, with an elevation of 90 feet.

"The horizon on this occasion, between the east and north, though continuous, appeared curiously undulated. There appeared a difference of nearly a quarter of a degree, between the elevation of the highest and lowest portions of the circumferential boundary.

"I have occasionally observed other effects of atmospheric refraction, such as produce an inverted image of distant ships; an elevation of the bow or stern, and a peculiar distortion of the masts; a division of a ship in the middle, and a lengthening of the hull, &c; but the preceding having been more attentively studied in connection with the state of the atmosphere, they are more satisfactory, and consequently more worthy of particular detail.

"From the whole of these facts, the following remarks may be deduced.

"1st, That the curious refractions of the atmosphere in the polar regions, as far as they have been observed, have usually occurred in the evening or night, after a clear day.

"2d, That they are most frequent on the commencement or approach of easterly winds. And,

"3d, That they are, probably, occasioned by the commixture, near the surface of the land or sea, of two streams of air of different temperatures, so as to occasion an irregular deposition of imperfectly condensed vapour, which, when passing the verge of the horizon, may produce the phenomenon observed."

The following quotation from Sir David Brewster's excellent "Letters on Natural Magic," gives a concise detail of facts relative to this subject;

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Among the wonders of the natural world which are every day presented to us, without either exciting our surprise or attracting our notice, some are occasionally displayed which possess all the characters of supernatural phenomena. In the names by which they are familiarly known, we recognize the terror which they inspired, and even now, when science has reduced them to the level of natural phenomena, and developed the causes from which they arise, they still retain their primitive importance, and are watched by the philosopher with as intense an interest as when they were deemed the immediate effects of Divine power. Among these phenomena we may enumerate the Spectre of the Brocken, the Fata Morgana of the Straits of Messina, the Spectre Ships,

which appear in the air, and the other extraordinary effects of the Mirage.

"The Brocken is the name of the loftiest of the Hartz Mountains, a picturesque range which lies in the kingdom of Hanover. It is elevated 3300 feet above the sea, and commands the view of a plain seventy leagues in extent, occupying nearly the 200dth part of the whole of Europe, and animated with a population of above five millions of inhabitants. From the earliest periods of authentic history, the Brocken has been the seat of the marvellous. On its summits are still seen huge blocks of granite, called the Sorcerer's Chair and the Altar. A spring of pure water is known by the name of the Magic Fountain, and the Anemone of the Brocken is distinguished by the title of the Sorcerer's Flower. These names are supposed to have originated in the rites of the great Idol Cortho, whom the Saxon's worshipped in secret on the summit of the Brocken, when Christianity was extending her benignant sway over the subjacent plains.

"As the locality of these idolatrous rites, the Brocken must have been much frequented, and we can scarcely doubt that the spectre which now so often haunts it at sun-rise must have been observed from the earliest times; but it is no where mentioned that this phenomenon was in any way associated with the objects of their idolatrous worship. One of the best accounts of the spectre of the Brocken is that which is given by M. Haue, who saw it on the 23d of May 1797. After having been on the summit of the mountain no less than thirty times, he had at last the good fortune of witnessing the object of his curiosity. The sun rose about four o'clock in the morning through a serene atmosphere. In the south-west, towards Achtermannshohe, a brisk west wind carried before it the transparent vapours, which had not yet been condensed into thick heavy clouds. About a quarter past four he went towards the inn, and looked round to see whether the atmosphere would afford him a fine prospect towards the south-west, when he observed at a very great distance, towards Achtermannshohe, a human figure of

I

a monstrous size. His hat, having been almost carried away by a violent gust of wind, he suddenly raised his hand to his head, to protect his hat, and the colossal figure did the same. He immediately made another movement by bending his body,-an action which was repeated by the spectral figure. M. Haue was desirous of making farther experiments, but the figure disappeared. He remained, however, in the same position, expecting its return, and in a few minutes it again made its appearance on the Achtermannshohe, when it mimicked his gestures as before. He then called the landlord of the inn, and having both taken the same position which he had before, they looked towards the Achtermannshohe but saw nothing. In a very short space of time, however, two colossal figures were formed over the above eminence, and after bending their bodies and imitating the gestures of the two spectators, they disappeared. taining their position, and keeping their eyes still fixed upon the same spot, the two gigantic spectres again stood before them, and were joined by a third. Every movement that they made was imitated by the three figures, but the effect varied in its intensity, being sometimes weak and faint, and at other times strong and well defined.

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"In the year 1798 M. Jordan saw the same phenomenon at sunrise, and under similar circumstances, but with less distinctness, and without any duplication of the figures.

"Phenomena perfectly analogous to the preceding, though seen under less imposing circumstances, have been often witnessed. When the spectator sees his own shadow opposite to the sun upon a mass of thin fleecy vapour passing near him, it not only imitates all his movements, but its head is distinctly encircled with a halo of light. The aerial figure is often not larger than life, its size and its apparent distance depending, as we shall afterwards see, upon particular causes. I have often seen a similar shadow when bathing in a bright summer's day in an extensive pool of deep water. When the fine mud deposited at the bottom of the pool is dis

turbed by the feet of the bather, so as to be disseminated through the mass of the water in the direction of his shadow, his shadow is no longer a shapeless mass formed upon the bottom, but is a regular figure formed upon the floating particles of mud, and having the head surrounded with a halo, not only luminous, but consisting of distinct radiations.

One of the most interesting accounts of aerial spectres with which we are acquainted has been given by Mr. James Clarke, in his Survey of the Lakes of Cumberland, and the accuracy of this account was confirmed by the attestations of two of the persons by whom the phenomena were first seen. On a summer's evening in the year 1743, when Daniel Stricket, servant to John Wren of Wilton Hall, was sitting at the door along with his master, they saw the figure of a man with a dog pursuing some horses along Souterfell side, a place so extremely steep that a horse could scarcely travel upon it at all. The figures appeared to run at an amazing pace, till they got out of sight at the lower end of the fell. On the following morning Stricket and his master ascended the steep side of the mountain, in full expectation of finding the man dead, and of picking up some of the shoes of the horses, which they thought must have been cast while galloping at such a furious rate. Their expectations, however, were disappointed. No traces either of man or horse could be found, and they could not even discover upon the turf the single mark of a horse's hoof. These strange appearances, seen at the same time by two different persons in perfect health, could not fail to make a deep impression on their minds. They at first. concealed what they had seen, but they at length disclosed it, and were laughed at for their credulity.

"In the following year, on the 23d June 1744, Daniel Stricket, who was then servant to Mr Lancaster of Blakehills, (a place near Wilton Hall, and both of which places are only about half a mile from Souterfell,) was walking, about seven o'clock in the evening, a little above the house, when he saw a troop of horsemen riding on Souterfell side in pretty close ranks, and at a