The apparitions of Swedenborg were probably caused by his studies, habits, and pursuits. They bear the marks of earthly origin, although he firmly believed they were from heaven. Overloading his stomach at late meals, no doubt, caused some of them. He was in the habit of eating too much, as he himself admits. Hence his brain may have been disturbed. We have all heard of the case of an elderly lady, who, being ill, called upon her physician one day for advice. She told him, among other things, that on the preceding night her sleep had been disturbed—that she had seen her grandmother in her dreams. Being interrogated whether she ate any thing the preceding evening, she told the doctor she ate half a mince pie just before going to bed. "Well, madam," said he, "if you had eaten the other half, you might have seen your grandfather also."
The slightest examination of the accounts which remain of occurrences that were deemed supernatural by our ancestors will satisfy any one, at the present day, that they were brought about by causes entirely natural, although unknown to them. We will close this part of our investigation by relating the following circumstances, attested by the Rev. James Pierpont, pastor of a church in New Haven:—
"In the year 1647, a new ship of about one hundred and fifty tons, containing a valuable cargo, and several distinguished persons as passengers, put to sea from New Haven in the month of January, bound to England. The vessels that came over the ensuing spring brought no tidings of her arrival in the mother country. The pious colonists were earnest and instant in their prayers that intelligence might be received of the missing vessel. In the course of the following June, a great thunder storm arose out of the north-west; after which, (the hemisphere being serene,) about an hour before sunset, a ship of like dimensions of the aforesaid, with her canvas and colors abroad, (although the wind was northerly,) appeared in the air, coming up from the harbor's mouth, which lies southward from the town, seemingly with her sails filled, under a fresh gale, holding her course north, and continuing under observation, sailing against the wind, for the space of half an hour. The phantom ship was borne along, until, to the excited imaginations of the spectators, she seemed to have approached so near that they could throw a stone into her. Her main topmast then disappeared, then her mizzen topmast, then her masts were entirely carried away, and finally her hull fell off, and vanished from sight, leaving a dull and smoke-colored cloud, which soon dissolved, and the whole atmosphere became clear. All affirmed that the airy vision was a precise copy of the missing vessel, and that it was sent to announce and describe her fate. They considered it the spectre of the lost ship, and the Rev. Mr. Davenport declared in public 'that God had condescended, for the quieting of their afflicted spirits, this extraordinary account of his sovereign disposal of those for whom so many fervent prayers were made continually.'"
The results of modern science enable us to explain the mysterious appearance. It is probable that some Dutch vessel, proceeding slowly, quietly, and unconsciously on her voyage from Amsterdam to the New Netherlands, happened at the time to be passing through the Sound. At the moment the apparition was seen in the sky, she was so near, that her image was painted or delineated to the eyes of the observers, on the clouds, by the laws of optics, now generally well known, before her actual outlines could be discerned by them on the horizon. As the sun sunk behind the western hills, and his rays were gradually withdrawn, the visionary ship slowly disappeared, and the approach of the night, while it dispelled the vapors from the atmosphere, effectually concealed the vessel as she continued her course along the Sound.
The optical illusions that present themselves, on the sea shore, by which distant objects are raised to view, the opposite islands and capes made to loom up, lifted above the line of the apparent circumference of the earth, and thrown into every variety of shape which the imagination can conceive, are among the most beautiful phenomena of nature, and they impress the mind with the idea of enchantment and mystery, more perhaps than any others. But they have received a complete solution from modern discovery.
It should be observed that the optical principles that explain these phenomena have recently afforded a foundation for the science, or rather the art, of nauscopy. There are persons, it is said, in some places in the Isle of France, whose calling and profession it is to ascertain and predict the approach of vessels by their reflection in the atmosphere and on the clouds, long before they are visible to the eye or through the glass.
Our vision is at all times liable to be disturbed by atmospheric conditions. So long as the atmosphere between our person and the object we are looking at is of the same density, we may be said to see in a straight line to the object. But if, by any cause, a portion of that atmosphere is rendered less or more dense, the line of vision is bent, or refracted, from its course. A thorough comprehension of this truth in science has banished a mass of superstition. It has been found that, by means of powerful refraction, objects at great distances, and round the back of a hill, or considerably beneath the horizon, are brought into sight. In some countries this phenomenon is called mirage. The following is one of the most interesting and best-authenticated cases of the kind. In a voyage performed by Captain Scoresby, in 1822, he was able to recognize his father's ship, when below the horizon, from the inverted image of it which appeared in the air. "It was," says he, "so well defined, that I could distinguish, by a telescope, every sail, the general rig of the ship, and its particular character, insomuch that I confidently pronounced it to be my father's ship, the Fame,—which it afterwards proved to be—though on comparing notes with my father, I found that our relative position, at the time, gave our distance from one another very nearly thirty miles, being about seventeen miles beyond the horizon, and some leagues beyond the limit of direct vision!"
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 part of the masts. The hull 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 completely upside down.
In the sandy plains of Egypt, the mirage is seen to great advantage. These plains are often interrupted by small eminences, upon which the inhabitants have built their villages in order to escape the inundations of the Nile. In the morning and evening, objects are seen in their natural form and position; but when the surface of the sandy ground is heated by the sun, the land seems terminated, at a particular distance, by a general inundation; the villages which are beyond it appear like so many islands in a great lake; and an inverted image of a village appears between the hills.
The Swedish sailors long searched for a supposed magic island, which, from time to time, could be descried between the Island of Aland and the coast of Upland. It proved to be a rock, the image of which was presented in the air by mirage. At one time, the English saw, with terror, the coast of Calais and Boulogne, in France, rising up on the opposite side of the Channel, and apparently approaching their island. But the most celebrated example of mirage is exhibited in the Straits of Messina. The inhabitants of the Calabrian shore behold images of palaces, embattled ramparts, houses, and ships, and all the varied objects of towns and landscapes, in the air—being refracted images from the Sicilian coast. This wonderful phenomenon is superstitiously regarded by the common people as the work of fairies.