Sound is nothing but a succession of vibrations of greater or less magnitude. Pitch is produced by the number of vibrations; intensity by their force; and quality by the character of the article vibrated.
Since the great telephone controversy which took place some years ago there has been a wonderful development in the knowledge of acoustics, or sounds. It was shown that the slightest sound would immediately set into vibration every article of furniture in a room, and very sensitive instruments have been devised to register the force and quality.
It is known that the chemical action of an object on a photographer's plate is due to vibration; each represents a force of different intensity, hence the varying shades produced. Owing to the different rates of vibrations caused by the different colors, the difficulty has been to photograph them, but this has now been accomplished. Harmony, or "being in tune," as is the common expression, is as necessary in light, as in music.
Some chemicals will bring out or "develop," the pictures; others will not. Colors are now photographed because invention and science have found the harmonizing chemicals.
One of the most remarkable of all the wonders of our age is what is known as duplex and quadruplex telegraphy. Every atom and impulse in electricity is oscillation. The current which transmits a telegram is designated in the science as "vibratory."
But how is it possible to transmit two or more messages over one wire at the same time? It is by bringing into play the harmony of sounds. One message is sent in one direction in the key of A; another message in the other direction in B; and so any number may be sent, because the electrical vibrations may be tuned, just like the strings of a violin.
Every sound produces a corresponding vibration in surrounding objects. While each vibrates, or is capable of transmitting a sound given to it by its vibratory powers, it may not vibrate in harmony.
When a certain key of a piano is struck every key has a certain vibration, and if we could separate it from the other sounds, it would reflect the same sound as the string struck, just the same as the walls of a room or the air itself would convey that sound.
But as no two strings in the instrument vibrate the same number of times each second, the rapid movement of successive sounds of the keys do not interfere with each other. If, however, there are several pianos in a room, and all are tuned the same pitch, the striking of a key on one instrument will instantly set in vibration the corresponding strings in all the other instruments.
This is one reason why a piano tested in a music wareroom has always a more beautiful and richer sound than when in a drawing-room or hall, since each string is vibrated by the other instrument.
If a small piece of paper is balanced upon the strings of a violin, every key of the piano may be struck, except the one in tune, without affecting the paper; but the moment the same key is struck the vibration of the harmonizing pitch will unbalance the paper.
The musical sound of C produces 528 vibrations per second; D 616, and so on. The octave above has double the number of vibrations of the lower note. It will thus be understood why discord in music is not pleasant to the ear, as the vibrations are not in the proper multiples.
So with odors. The sense of smell is merely the force set in motion by the vibration of the elements. An instrument called the odophone demonstrates that a scale or gamut exists in flowers; that sharp smells indicate high tones and heavy smells low tones. Over fifty odors have thus been analyzed.
The treble clef, note E, 4th space, is orange; note D, 1st space below, violet; note F, 4th space above clef, ambergris. To make a proper bouquet, therefore the different odors must be harmonized, just the same as the notes of a musical chord are selected.
The odophone shows that santal, geranium, orange flower and camphor, make a bouquet in the key of C. It is easy to conceive that a beautiful bouquet means nothing more than an agreeable vibratory sensation of the olfactory nerves.
So with the sense of taste. The tongue is covered with minute cells surrounded by nervous filaments which are set in motion whenever any substance is brought into contact with the surface. Tasting is merely the movement of these filaments, of greater or less rapidity.
If an article is tasteless, it means that these filaments do not vibrate. These vibrations are of two kinds. They may move faster or slower, or they may move in a peculiar way. A sharp acute taste means that the vibrations are very rapid; a mild taste, slow vibrations.
When a pleasant taste is detected, it is only because the filaments are set into an agreeable motion. The vibrations in the tongue may become so rapid that it will be painful, just as a shriek becomes piercing to the ear, or an intense light dazzling to the eye; all proceed from the same physical force acting on the brain
Color, that seemingly unexplainable force, becomes a simple thing when the principles of vibration are applied, and this has been fully explained by the spectroscope and its operation.
When the boy once appreciates that this force, or this motion in nature is just as simple as the great inventions which have grown out of this manifestation, he will understand that a knowledge of these things will enable him to utilize the energy in a proper way.