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Musical Courier 1892-12-21: Vol 25 Iss 668, 1892
34 lines. Read by computer on 23 September 2026. Printed page 57. See the scan on archive.org.
1constructed of wood we must consider the action and strings, whose office it is to set it in vibration.
3THE STRINGS.
5The part of a piano that is the exclusive property and invention of the maker is the "scale." This means the whole plan and proportion of the instrument, and also, in a narrower sense, its stringing, which depends upon the behavior of a string under varying conditions. The contrivance I place before you is a monochord. The first ever seen in Europe was brought from Egypt by Pythagoras, therefore consonant. The seventh partial is somewhat dissonant; the ninth, tenth, &c., equally so. Helmholtz therefore thinks it desirable to have the first six partials well developed in a piano string, but not the seventh, and still less the ninth and higher overtones. Various things enter into the question: the thickness of the string, its length, its tension, its weight. The carrying property of a tone depends largely upon its constituent partials, and its delicacy still more; but before we arrive at the question of carrying, we must consider equality.
7There is a long series of measurements of the length and one, and thereby sound the octave of the latter. Again, let two be alike, except as to tension. If one be stretched with four times the stress of the other, it will vibrate twice as fast, and hence produce the octave of the looser string. Let it be twice as heavy, it will vibrate only one half as fast—that is, inversely as its weight. Now it is impossible to arrange the scale of a piano in such a way as to double the length of the strings for each octave. The pitch is therefore planned with reference to the mutual effect of length, tension, weight and thickness—a very nice problem indeed. If a string be too thin, it will not allow of a sufficiently heavy blow from the hammer, and the tone will be feeble. If the string be too much weighted, it will not yield its partials, and the tone will not carry or vibrate any length of time. Too heavy strings quickly lose their proper pitch. I have heard uprights so defective in this respect that their lower notes lost their definite pitch at a little distance from the instrument, and sounded like the noise of a drum.
9The thickest bass string of the first pianos was thinner than the thinnest treble string of a modern instrument. It is the study of modern piano makers to produce a scale with thick strings under high tension; because a string stretched to the limit of its tenacity yields the strongest transverse vibrations and the purest and most brilliant tone. Now, a string possesses different kinds of vibration, as Marloye long since discovered. It vibrates transversely when it forms the nodes, and consequently the partial tones of which we have been speaking. But it may vibrate molecularly—that is, the sound wave may move onward from molecule to molecule. This is the kind of vibration whose velocity Wertheim measured on telegraph wires—a vibration which years ago was utilized in the first telephone. The transverse vibration may be rotary. Marloye made it visible by attaching two colored riders to adjacent internodes of a vibrating string. He saw them revolve briskly in different directions. The rotary vibration of bass strings is sought by piano makers. To promote it they arrange their hammers to strike obliquely.
11Toward the close of the last century John Broadwood calculated the tension of his piano strings in order to equalize it, and so formulated the notion of a correct measurement of the string scale. Thomas Loud, of London, made a cross strung upright as early as 1802. In 1830 he was building cross strung pianos in New York. Babcock, of Boston, introduced a cross strung scale in the same year. Jonas Chickering patented an overstrung circular scale in 1845. The next step toward the present theory of stringing was taken by the Steinways, who divided their strings into webs, and arranged them in the form of a fan—the bridges in the centre of a soundboard, the bass strings crossing the treble. This obtained two advantages: a better vibration for the strings, on account of their greater length; and a more complete vibration of the soundboard.
13Nineteen years after the founding of their house the Steinways patented their duplex scale, the complement of that fan formed stringing which won their first triumph. We have seen the spontaneous division of the string into equal parts, each vibrating separately at the same time that the entire string vibrates as a whole—each vibrating segment of the string producing a partial tone.
15Mr. Steinway arranged the transverse capo d'astro bar so that it took the place of agraffes in the treble, and cut off a section of the string near the tuning pin the exact length of one of the vibrating sections of the entire string. The bar touches the string, and forms a node; the end of the string thus cut off vibrates with the main part of the string, and, reacting on it, reinforces the partial tone to which its own vibration corresponds, and compels the formation of all the desirable intermediate partials. The other end of the string, between the bridge and the hitch pin, is also an aliquot part of the main string. In this case the bridge forms not a node, but an impassable bar; nevertheless, this section of string vibrates sympathetically with the main string. We remember the researches of Wheatstone, by which he showed that any substance will be set in sounding vibration by the air wave, the proportions of which will permit it to vibrate in the same periodic time. In this way the string behind the bridge reinforces the partial tone to which its length, thickness and tension correspond. This scale, which rests upon the scientific investigations of
17A BROADWOOD SQUARE, DATED 1809, NOW IN POSSESSION OF STEINWAY & SONS.
19This piano, which was exhibited when these lectures were first delivered, is too old to bear repairing, but shows its various peculiarities of construction unaltered.
21some 400 years before the Christian era. Upon this wire string I hope to show what is meant by nodes, partial tones and transverse vibrations. With my violin bow I set the string in vibration. You all hear its tone. The note, like all others with which we are familiar, is a compound formed by the union of several partial tones, all made by the vibrations of this single string. To quote Mr. Marloye: "A string on which we act transversely can resound only on condition that it can yield at least two transverse sounds, of which the higher will depend on the part acted on or on the mode of inducing the vibrations." Here are two paper riders. I place them upon the string, across which I draw my bow. Both are thrown off by the vibrations. I replace them, one in the middle of the string and one at a quarter of its length. I draw my bow across the string near the end, and both remain in place. These quiet points of the string are called nodes. They are the points where it divides to form its partial tones. I damp it lightly on its centre, and so withdraw the fundamental without eliminating the second partial tone, which you now hear an octave higher. The violinist calls such partials harmonics. By varying the place where the bow attacks the string, I can vary the formation of the nodes, and thus select the partial tones which they determine. A piano string struck by a hammer not only vibrates as a whole, but separates itself into nodes and internodes, giving rise to a long series of partial tones.
23I will play you a little study in partial notes excited by sympathetic vibration, quoted from Hans Schmitt's book on the pedal. I press middle c down without making any sound, and hold up its damper with the tone sustaining thickness of the strings between the bass and the upper treble. How shall they be graduated so that the tones make a perfectly even series from bottom to top? That difference in the tone quality of the strings which lends itself to expression in a violin would be fatal in a piano; but the life struggle of the violinist to make his a and e strings agree in quality is the struggle of the piano maker throughout the entire scale. The tone of the loveliest violin in the world is hopelessly ruined if the e string be too thick for the a, or as happens oftener, the a too thick for the e. When a violinist wishes to produce a robust tone he uses rather thick strings and bears on his bow; but if he wishes a pure, brilliant and at the same time delicate tone he chooses thin strings, and does not allow the weight of his arm to come upon the string the value of a hair.
25Such a bowing, depending on the strength and elasticity of the player's arm, will produce a tone which will seem free in the air. It is the study of the piano maker to bring about similar conditions, and yet augment the power of his instrument to the utmost. The first consideration is, of course, to produce the requisite pitch without introducing several different qualities of tone. Observe the complications. The pitch of strings depends upon the rapidity of their vibration. This rapidity depends upon their length, thickness, tension, stiffness and weight. Brass, silver, platinum, steel, gold, copper are of different weights—all have been tried. Since the weight of the string conditions the rapidity of its vibration, where short strings are required to produce a low tone mixtures of heavy metals are made to reduce the pitch. Modern practice gives steel for the treble, and steel overspun with copper for the bass. Silver, which vibrates with a very clear tone, though useful for small instruments, has too little tenacity for pianos.
27The pitch of a string varies inversely as its length. Imagine three strings; let one be twice as long as the other, but in thickness, weight of material, tension, exactly similar. The short one will vibrate twice as fast as the long
29A NUNNS & CLARK PIANO, IN POSSESSION OF STEINWAY & SONS.
31Compare the soundboard, the soundboard bridge, the hitch pins, the wrest pins and the upper bracing with corresponding parts of the Broadwood and of the Steinway (shown elsewhere).
33pedal. Now I play the chords firmly, but staccato, and you can faintly hear an upper voice singing in harmonics upon the c which has not been struck at all. You must all hold your breath, for they are very delicate notes. The first six partials of a vibrating string comprise the notes of the common chord built upon its fundamental tone, and are
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