The Æolian Harp consists of an oblong box of thin deal board, about five or six inches deep, with a circle drawn in the middle of the upper side, an inch and a half in diameter, around which are to be drilled small holes. Along the upper side of the box seven, ten, or more small strings, of very fine gut, are stretched over bridges near each end, like the bridges of a violin, and tightened or relaxed with screw pins. The strings must be tuned to one and the same note, and the instrument placed in some current of air where the wind can pass over its strings with freedom. A window, the width of which is exactly equal to the length of the harp, with the sash just raised to give the air admission, is a good situation. When the wind blows upon the strings, with various degrees of force, different musical tones will be sounded; sometimes the blast brings out all the tones in full concert, and sometimes it sinks them to the softest murmur. In many old castles these harps were fastened in the windows, and their wild music caused the ignorant to think they were haunted.

A colossal imitation of the instrument just described was invented at Milan, in 1786, by Abbate Gattoni. He stretched seven strong iron wires, tuned to the notes of the gamut, from the top of a tower sixty feet high, to the house of a Signor Muscate, who was interested in the success of the experiment and this apparatus, called the giant’s harp, in blowing weather, yielded lengthened peals of harmonious music. In a storm this music was sometimes heard at the distance of several miles.

Simply tying waxed saddler’s silk to little sticks, and pushing them into the crevices of windows, so as to receive a draught of wind (the silk being strained tight), will produce very sweet sounds.

1.—THE MAGIC OF ACOUSTICS.

The science of acoustics furnished the ancient sorcerers with some of their most complete deceptions. The imitation of thunder in their subterranean temples did not fail to indicate the presence of a supernatural agent. The golden virgins, whose ravishing voices resounded through the temple of Delphos; the stone from the river Pactolus, where trumpet notes scared the robber from the treasure which it guarded; the speaking head, which uttered its oracular responses at Lesbos; and the vocal statue of Memnon, which began at the break of day to accost the rising sun, were all deceptions derived from science, and from a diligent observation of the phenomena of nature.

2.—TO SHOW HOW SOUND TRAVELS THROUGH A SOLID.

Take a long piece of wood, such as the handle of a broom, place a watch at one end, apply your ear to the other, and the ticking will be distinctly heard.

3.—THEORY OF THE VOICE.

Provide a species of whistle common as a child’s toy, or a sportsman’s call, in the form of a hollow cylinder, about three fourths of an inch in diameter, closed at both ends by flat circular plates with holes in their centres. Hold this toy between the teeth and the lips; blow through it, and you can produce sounds, varying in pitch with the force with which you blow. If the air be cautiously graduated, all the sounds within the compass of a double octave may be produced from it, and if great precaution be taken in the management of the breath even deeper tones may be brought out. This simple instrument or toy, has indeed the greatest resemblance to the larynx, which is the organ of the voice.

4.—A SINGULAR EXAMPLE OF SUPERSTITION.

The following true story was related to me by one who was personally acquainted with the facts. There was a certain bend in one of our western rivers which was avoided by every one, as it was supposed to be haunted by the devil. At a certain hour in the evening, for many years, terrible curses were distinctly heard. Suddenly they ceased. A gentleman skilled in the science of acoustics, hearing an account of the strange phenomena, determined to ascertain the cause, and carefully examined the river on each side for about a mile above and below the bend. He ascertained that at about the time the sounds ceased, an old fisherman, who had lived on the opposite side of the river, full a mile from the spot where the curses were heard, had died. He was told that the fisherman was in the habit of crossing the river to a village, where he found a market for his fish, and where he spent his money for liquor; and that after drinking freely on his way home, while rowing across the river at night, he would swear terribly. This gentleman then persuaded a friend to go down the river to the place where the curses were formerly heard, while he remained in a boat on the river at the point at which the old man usually crossed. He then played on a bugle and sang several songs. His friend soon returned, and with eager delight exclaimed, “O, ——, such glorious music fills the air, just where the curses used to be heard!” The neighbors came rushing down to hear it, and some fell on their knees, praying. They said, “the angels have driven the devil away.” Mr. —— then asked what were the songs they heard. His friend described them correctly, and said he understood even the words, one of them being the famous Marseillaise, another a German song; the foreign words made the ignorant more sure that the sounds were supernatural. Mr. —— then played on the bugle, and sang again the same songs, while his friend stood by; but his friend said the music was not equal to that he had heard below, where the sounds had really seemed heavenly.

The peculiar configuration of the river banks had concentrated the sounds, and the distance and the water had softened them.

The person who related this anecdote to me said that he and his friend had often tried the experiment. Nothing would convince the more ignorant neighbors that the sounds were occasioned by merely natural causes. A love of the supernatural is strong within us, and sometimes leads us into grave mistakes.