Part 38

These optical appearances of figures in the sea and air, in the Faro of Messina, are the great delight of the populace, who, whenever the vision is displayed, run about the streets shouting for joy, and calling on every one to partake of the glorious sight. To produce this pleasing deception, many circumstances must concur which are not known to exist in any other situation. The spectator must stand with his back to the east, in some elevated place behind the city, that he may command a view of the whole bay, beyond which the mountains of Messina rise like a wall, and darken the background of the picture. The winds must be hushed, the surface of the water quite smooth, the tide at its hight, and the waters pressed up by currents to a great elevation in the middle of the channel. All these events coinciding, as soon as the sun surmounts the eastern hills behind Reggio, (on the Calabrian coast opposite,) and rises high enough to form an angle of forty-five degrees on the water before the city, every object, existing or moving at Reggio, will be repeated a thousand-fold in this marine mirror, which, by its tremulous motion, is, as it were, cut into facets. Each image will pass rapidly off in succession, as the day advances, and the stream carries down the wave on which it appeared. Thus the parts of this moving picture will vanish in the twinkling of an eye. Sometimes the air is at this time so impregnated with vapors, and undisturbed by winds, as to reflect objects in a kind of aerial screen, rising about thirty feet above the level of the sea. In cloudy, heavy weather, they are drawn on the surface of the water, bordered with fine prismatic colors.

Swinburne, in his travels, cites Father Angelucci as having been the first to describe this phenomenon accurately. His relation is as follows. “On the fifteenth of August, 1643, as I stood at my window, I was surprised with a most wonderful and delectable vision. The sea which washes the Sicilian shore, swelled up, and became, for twelve miles in length, like a chain of dark mountains; while the waters near our Calabrian coast grew quite smooth, and in an instant appeared as one polished mirror, reclining against the aforesaid ridge. On this glass was depicted, in _chiar-oscura_, a string of several thousands of pilasters, all equal in altitude, distance and degree of light and shade. In a moment they lost half their hight, and bent into arcades, like Roman aqueducts. A long cornice was next formed on the top, and above it rose castles innumerable, all perfectly alike. These soon split into towers, which were shortly after lost in colonnades, then in windows, and at last ended in pines, cypresses, and other trees, even and similar. This was the Fata Morgana, which, for twenty-six years, I had thought a mere fable.”

ATMOSPHERICAL REFRACTION.

A surprising instance of atmospherical refraction occurred at Hastings, England, on the twenty-sixth of July, 1798. W. Latham, Esq., sitting in his dining-room, situated on the parade, close to the sea-shore, and nearly fronting the south, about five in the afternoon, had his attention suddenly drawn by a great number of people running down to the seaside. On inquiring the reason, he was informed that the coast of France was plainly to be distinguished by the naked eye. On going down to the shore, he was surprised to find that, even without the assistance of a telescope, he could very plainly see the cliffs on the opposite coast; which, at the nearest part, are between forty and fifty miles distant, and are not to be discerned, from that low situation, by the aid of the best glasses. They appeared to be only a few miles off, and seemed to extend for some leagues along the coast. Pursuing his walk along the shore to the eastward, close to the water’s edge, and conversing on the subject with the sailors and fishermen, they could not, at first, be persuaded of the reality of the appearance; but soon became so thoroughly convinced, by the cliffs gradually appearing more elevated, and approaching nearer as it were, that they pointed out and named to him the different places they had been accustomed to visit, such as, the Bay, the Old Head or Man, the Windmill, &c., at Boulogne; together with St. Vallery, and other places on the coast of Picardy. This they afterward confirmed, when they viewed them, thus refracted, through their telescopes, observing that the above places appeared as near as if they had been sailing, at a small distance, into the harbors. From the eastern cliff, which is of a very considerable hight, a most beautiful scene presented itself to Mr. Latham’s view, for there he could at once see Dungeness, Dover cliffs, and the French coast, all along from Calais, Boulogne, &c., to St. Vallery; and, as some of the fishermen affirmed, as far to the westward even as Dieppe. By the telescope, the French fishing-boats were plainly to be seen at anchor, and the different colors of the land on the hights, with the buildings, were perfectly discernible. This curious phenomenon continued in the highest splendor till half past eight o’clock, notwithstanding a black cloud for some time totally obscured the face of the sun, and then vanished gradually. So remarkable an instance of atmospherical refraction had not been before witnessed by the oldest inhabitant of Hastings. It was likewise observed at Winchelsea, and other places along the coast. The day was remarkably hot, without a breath of wind stirring.

As another instance of this refracting power of the atmosphere, Dr. Vince, an English philosopher, was once looking through a telescope at a ship, which was so far off, that he could only see the upper parts of the masts. The hulk was entirely hidden by the bending of the water, but between himself and the ship he saw two perfect images of it in the air. These were of the same form and color as the real ship; but one of them was turned upside down. And when Captain Scoresby was in the polar sea with his ship, he was separated by the ice from that of his father for some time, and looked out for her every day with great anxiety. At length, one evening, to his utter astonishment, he saw her suspended in the air, in an inverted position, traced on the horizon in the clearest colors, and with the most distinct and perfect representation. He sailed in the direction in which he saw this visionary phenomenon, and actually found his father’s vessel by its indication. He was separated from the ship by immense masses of icebergs, and at such a distance that it was impossible to have seen her in her actual situation, or to have seen her at all, if her spectrum had not been thus raised several degrees above the horizon in the air by this most extraordinary refraction. It is by this bending of the rays of light that the images of people are often seen at a distance, and sometimes magnified to a gigantic size. We have given an account of such an appearance in the Hartz mountains, in Germany.

Another singular instance of the refracting power of the atmosphere, was witnessed within the present year, (1854,) by Mr. Elliott, the aeronaut, while ascending in his balloon from Petersburg, Virginia. After he had ascended about three thousand feet he discharged some five pounds of ballast, when he shot onward and upward with amazing rapidity till he began to approximate to the clouds. He then discharged about five pounds more of sand, the remainder of the bag, when he again darted upward among the clouds, which were so dense as to wholly exclude all terrestrial objects from his view, and of course he was lost to all observers below. These discharges were distinctly seen by persons watching him, and on the first occasion some one exclaimed that the balloon had burst. While among the clouds, it seemed to him as if he was in the midst of a large ground-glass globe, some two or three hundred feet in diameter, against the side of which opposite to the sun, the shadow of his balloon rested, some five or six times larger than the corporeal one. About half-way between him and the shadow, which seemed as if resting on the glass wall, another balloon was seen, of a size between the shadow and the real one, resting as if in a vacuum, which displayed every color of the original faithfully. He then saw another Elliott, clad and with features like himself, and seemingly self-like. He then extended his own fingers, when he was mimicked by his image; and whether he extended one finger or more, or whatever he did, this figure duplicated exactly. When he would cause his balloon to oscillate, this balloon would move exactly like his. When he threw out more ballast to elevate himself, this figure _sank down_ instead of rising with him; and when he arose above the clouds into the rays of the unclouded sun, he left the mimic aeronaut below him.

In the rays of the sun above the clouds he found it so warm as to cause him to perspire freely, a state of heat never before experienced at this hight, nearly twenty-four thousand feet, where the air is very rarefied and generally very chilly. He then opened the valve for the purpose of descending, and as soon as he had sunk one or two thousand feet, which he ascertained by barometrical indications, he felt as if he had entered an ice-house, and a cold chill seized his whole person. Here he again met his mimic aerial voyager, whom he kept in company for some time, from philosophical motives. Whenever he moved sideways, this _mum_ gentleman would move in the same direction. But when he moved up or down, the duplicate would move in a directly opposite way; and when he concluded to descend, the image moved upward until the tricolored flag was out of sight, when he could see the car and the aeronaut still standing in it as if in a basket attached to nothing. He continued to look until his head was Robespierred, and finally, piece by piece, his body, and, at last, his feet and basket, ascended out of his sight. Mr. Elliott said that he had been up a hundred and one times, but never had seen anything in the form of an illusion like this before.

[Illustration: SHIP REFRACTED IN THE AIR.]

But one of the most remarkable cases of atmospheric refraction of which we have any record, is that which occurred at New Haven, Connecticut, in the early settlement of the colony. The colonists had built a ship, and freighted her for England with a valuable cargo, with which she sailed from their harbor in the winter of 1647, having several of their principal men on board. They were obliged to cut their way through the ice to get out of the harbor; and the ship, never being heard of afterward, was supposed to have foundered at sea. No tidings arriving of the ship or of her fate, the colonists were deeply distressed, and “were very earnest in their prayers, both public and private, that God would in some way make manifest to them what had become of their friends.” In the following June, a violent thunder-storm arose out of the north-west, after which the atmosphere being very calm and serene, about an hour before sunset, a ship of the dimensions and form of the one they had lost, with all her canvas set and flags flying, appeared in the air, coming up the harbor, her sails filled as though by a fresh gale, and sailing against the wind, for the space of half an hour.

At length, as she came nearer, her maintop seemed to be blown off, though left hanging in the shrouds; then, her mizzen-top; then all her masting seemed blown away by the board; quickly after, her hulk careening, she overset, and seemed to sink and vanish in the clouds, and as these clouds passed away, the air where she was seen, was, as before, perfectly clear. The crowd of spectators could distinguish the appearance of the various parts of the ship, the principal rigging, and such proportions as made them satisfied that this was indeed their ship; and Mr. Davenport, the minister, declared, in public, that God, for the quieting of the hearts of the people, had given them this extraordinary exhibition and account of what he had done with their property and friends. But science gives us a more natural and less miraculous explanation of the matter, in the refracting power of the air when in certain states; and the probability is, that the ship, thus seen in the air, was some strange vessel (which they imagined looked like their own) coming up the harbor before the breeze, and then driven off and wrecked by the storm, which reached her after it had passed New Haven; or else that it was, indeed, their own ship, which after being driven about for months, was now coming back to her port, when she was thus caught in the tempest and destroyed. And as confirming this view of the matter, it may be added, in conclusion, that within the present century, it is said, a similar refraction of a ship in the air, has been witnessed in the same place.

PARHELIA, OR MOCK SUNS.

On the fifth of February, 1674, near Marienberg, in Prussia, the sky being everywhere serene, the sun, which was still some degrees above the horizon, was seen to lance out very long and reddish rays, forty or fifty degrees toward the zenith, notwithstanding it shone with great luster. Beneath this planet, toward the horizon, there hung a somewhat thin small cloud, at the inferior part of which there appeared a mock sun, of the same apparent size with the true sun, and of a reddish color. Soon after, the true sun descending gradually to the horizon, toward the said cloud, the spurious sun beneath it grew clearer and clearer, in so much that the reddish color in this apparent solar disk vanished, and it put on the genuine solar light, in proportion as it was approached by the genuine disk of the sun. The latter, at length, passed into the lower counterfeit sun, and thus remained alone. This phenomenon was considered the more wonderful, as it was perpendicularly under the sun, instead of being at its side, as parhelia usually are; not to mention the color, so different from that which is usual in mock suns, nor the great length of the tail cast up by the genuine sun, of a far more vivid and splendid light than parhelia commonly exhibit. This appearance was soon followed by an exceedingly intense frost, which lasted till the twenty-fifth of March, the whole bay being frozen up from the town of Dantzic to Hela in the Baltic sea.

On the twenty-eighth of August, 1698, about eight o’clock in the morning, there was seen at Sudbury, in Suffolk, England, the appearance of three suns, which were then extremely brilliant. Beneath a dark, watery cloud, in the east, nearly at its center, the true sun shone with such strong beams, that the spectators could not look at it; and on each side were the reflections. Much of the firmament was elsewhere of an azure color. The circles were not colored like the rainbow, but white; and there was also, at the same time, higher in the firmament, and toward the south, at a considerable distance from the other phenomena, the form of a half-moon, but apparently of double the size, with the horns turned upward. This appearance was, within, of a fiery red color, imitating that of the rainbow. These phenomena faded gradually, after having continued about two hours.

Two mock suns, an arc of a rainbow inverted, and a halo, were seen at Lyndon, in the county of Rutland, on the twenty-second of October, 1621, at eleven in the morning. There had been an =aurora borealis= the preceding night, with the wind at west-south-west. The two parhelia, or mock suns, were bright and distinct, and in the usual places, namely, in the two intersections of a strong and large portion of a halo, with an imaginary circle parallel to the horizon, passing through the true sun. Each parhelion had its tail of a white color, and in direct opposition to the true sun; that toward the east being some twenty or twenty-five degrees long, and that toward the west from ten to twelve degrees, both narrowest at the remote ends. The mock suns were evidently red toward the sun, but pale or whitish at the opposite sides, as was the halo also. Still higher in the heavens, was an arc of a curiously inverted rainbow, about the middle of the distance between the top of the halo and the vertex. This arc was as distinct in its colors as the common rainbow, and of the same breadth. The red color was on the convex, and the blue on the concave of the arc, which seemed to be about ninety degrees in length, its center being in or near the vertex. On the top of the halo was a kind of inverted bright arc. This phenomenon was seen on the following day, and, again, on the twenty-sixth. On the eleventh of the preceding month, September, a very splendid and remarkable =aurora borealis=, presenting truly unaccountable motions and removals, was witnessed in Rutlandshire, in Northamptonshire, and at Bath.

LUNAR RAINBOW.

This very rare phenomenon was witnessed at Glapwell Hall, in Derbyshire, England, on the twenty-fifth of December, 1710, about eight in the evening, with a remarkable and very unusual display of colors. The moon had passed her full about twenty-four hours, and the evening had been rainy; but the clouds were dispersed, and the moon then shone quite clear. This =iris lunaris= had all the colors of the solar iris, exceedingly beautiful and distinct, only faint in comparison with those which are seen in the day; as must necessarily have been the case, both from the different beams by which it was occasioned, and the disposition of the medium. What most surprised the observer was the largeness of the arc, which was not so much less than that of the sun, as the different dimensions of their bodies, and their respective distances from the earth, seemed to require; but the entireness and beauty of its colors furnished a charming spectacle.

CONCENTRIC RAINBOWS.

This extraordinary phenomenon, which is seen at sunrise on the Andes, in South America, was first witnessed by Ulloa and his companions in the wild heaths of Pambamarca, and is thus described by him. “At day-break the whole of the mountain was enveloped in dense clouds, which at sunrise were dissipated, leaving behind them vapors of so extreme a tenuity, as not to be distinguishable to the sight. At the side opposite to that where the sun rose on the mountain, and at the distance of about sixty yards from the spot where we were standing, the image of each of us was seen represented as if in a mirror, and three concentric rainbows, the last or most exterior colors of one of which touched the first of the following one, were centered on each head. Without the whole of them, and at an inconsiderable distance, was seen a fourth arc purely white. They were all perpendicular to the horizon; and in proportion as any one of us moved from one side to the other, he was accompanied by the phenomenon, which preserved the same order and disposition. What was, however, most remarkable, was this, that although six or seven persons were thus standing close together, each of us saw the phenomenon as it regarded himself, but did not perceive it in the others. This, adds Bouguer, is a kind of apotheosis, in which each of the spectators, seeing his head adorned with a glory formed of three or four concentric crowns of a very vivid color, each of them presenting varieties similar to those of the first rainbow, tranquilly enjoys the sensible pleasure of reflecting that the brilliant garland he can not discover in the others is destined for himself alone.”

A similar phenomenon is described by Mr. Hagarth, as having been seen by him in Wales, on the thirteenth of February, 1780. His relation is as follows. “In ascending, at Rhealt, the mountain which forms the eastern boundary of the vale of Clwyd, (in Denbighshire,) I observed a rare and curious phenomenon. In the road above me, I was struck with the peculiar appearance of a very white, shining cloud, which lay remarkably close to the ground. The sun was near setting, but shone extremely bright: I walked up to the cloud, and my shadow was projected into it, its superior part being surrounded, at some distance, by a circle of various colors, whose center appeared to be near the situation of the eye, and whose circumference extended to the shoulders. This circle was complete, except what the shadow of my body intercepted. It exhibited the most vivid colors, the red being outermost; and all of them appearing in the same order and proportion as they are presented to the view by the rainbow. It resembled very exactly what in pictures is termed a glory, surrounding the heads of saints; not indeed that it exhibited the luminous radiance that is painted close to the head, but an arch of concentric colors placed separately and distinctly from it. As I walked forward, this glory approached or retired, just as the inequality of the ground shortened or lengthened my shadow. The cloud being sometimes in a small valley below me, sometimes on the same level, or on higher ground, the variation of the shadow and glory became extremely striking and singular. To add to the beauty of the scene, there appeared, at a considerable distance to the right and left, the arches of a white, shining bow. These arches were in the form of, and broader than a rainbow; but were not completely joined into a semicircle above, on account of the shallowness of the cloud.”

THUNDER AND LIGHTNING.

To conceive justly of the nature of thunder and lightning, we have only to view the effects of a common electrical machine, and its apparatus, in an apartment. These experiments mimic the great, wonderful and terrific phenomena of nature. The stream, or spark, from the machine to the hand, represents the shaft of lightning from the clouds to the earth; and the snapping noise of the diminutive spark corresponds with the explosion produced by the lightning, which we call thunder. In what manner the clouds become electrified, and, in short, what is the nature of electricity itself, our present range of experiments so little qualify us to determine, that a century will perhaps elapse before a philosophical precision can be attained. At present we only know for certain that the electrical power displays itself merely on the surface of bodies; and whether it is a fluid =per se=, a vacuum restoring itself, or whatever its nature may be, the state of experimental knowledge does not enable us to determine.