and it stands on three or four short legs, in the same manner as an iron pot. These drums are always used in pairs, one being pitched to the key-note, and the other to a fourth below. In Rees's Cyclopædia, a work in which the articles on music and musical instruments are exceedingly valuable, we find the following very judicious remarks: "In some

instances three kettle-drums have been used. It were to be wished, that practice were more common; because not only could the kettle-drums then accompany in the key and its adjuncts, but when performing in the key, the perfect cadence could be completely supported by this powerful instrument." The instance given by the writer is a piece composed in C major, the third drum being tuned a fifth below the key; one would be C, another G, and the third F; the perfect cadence would therefore be obtained.

The kettle-drum is an instrument very common in many parts of Asia; it is in fact a royal instrument, and may always be found in the train of the monarch. Sometimes persons in authority will presume to adopt it, but this is not generally allowed. The Hindoos also use a pair of very

small kettle-drums, called tanblahs, which they carry before them. These are struck with the fingers, and by varying the intensity of the blow, and the point where it is struck, the tones are by no means unpleasant.

From what has been stated in this chapter, we may learn that the action of musical instruments does not entirely depend on the vibrations of the sounding body. In stringed instruments the sound is not produced by the vibration of the strings alone, but by the communication of those vibrations to the substances that surround them. The violin is an

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135

example already alluded to; and experiments have been mentioned to prove the absolute vibration of the body of the instrument. The pitch of a sound is regulated by certain immutable laws, and whatever may be the condition in which the vibrating body is placed, the pitch must always be the same, all things being equal; but the quality of the tone will be regulated, not only by the material of which the cord or string is produced, but also by the means adopted to excite the vibrations, and the circumstances under which the strings are placed. Every one can appreciate the difference in the quality of a tone obtained from a violin and guitar, a pianoforte and a harp.

The illustrations adduced to prove and explain the resonance of sound, open a new and very interesting field of inquiry. The weak and almost inaudible sound of a vibrating plate, becomes a rich and melodious tone, when a column of air is made to reciprocate to its vibrations. A new class of instruments will, therefore, now be introduced, and a pleasing variety be given to those which are especially designed for private performance. Considering how short a time the attention has been drawn to this principle, much has been accomplished; but we look forward to the period, and it is not probably far distant, when instruments formed of vibrating plates will be among those most esteemed for the softness and melodious harmony of their tones.

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CHAPTER VII.

VIBRATING COLUMNS OF AIR.

MANY persons imagine that the production of sound from flutes, trumpets, and other wind instruments, arises from the vibration of the wood or metal of which they are composed; but it is in fact entirely due to the air that is contained within them. This is evident from the circumstance that the pitch is always the same, the column of air being equal, whatever may be the thickness or character of the material employed in the construction of the pipe. Thus, for instance, a pipe of glass, and another of wood, would give out, under similar circumstances, precisely the same note. Flutes are made of wood, ivory, glass, and other substances, and yet the same tone may be obtained from all. It is true that the quality of a sound does in part depend on the substance of which the pipe is formed, for there will be a feeble vibration of the material arising from the friction of the air within, but it is to the motion of the air that the sound must be attributed.

Allusion has already been made to the analogy between the vibrations of air in a pipe, and the undulations of a stretched cord. It must be further observed that a column of air in a closed tube may be divided in the same manner, into ventral segments by nodes or points in a state of rest. Thus if the column of air be set in vibration from the centre

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137

of the column, there will be a constant motion on each side in opposite directions, and consequently a division into two aliquot parts.

Mr. Wheatstone has shown that a cylindric or prismatic column of air in an open tube may vibrate in any number of aliquot parts; and that in all cases the number of vibrations is inversely as the length of a single vibrating part. "As a column of air is capable of reciprocating every sound which, according to its different modes of vibration, it is itself capable of producing; supposing 1=C1 to represent the lowest sound of the tube, it will, without any change in its length,

reciprocate sounds whose relations are

7 8 Bb3' C4'

&c.

1 2 3 4 5 6 C C G C E3 G3

"The harmonic subdivisions of a column of air in a tube closed at one end, are different; a semi-vibrating part always exists near the closed end, but between two nodes, or a node and the open end, complete vibrating parts, as in an open tube, exists. The fundamental sound above mentioned of an open tube, is given by a tube closed at one end, of onehalf its length, the series corresponding with the subdivisions, 1 3 5 7 9 compared with the above, is CG E3 Bb3' D'

these sounds it can consequently reciprocate."

&c., and

Before we enter further into the consideration of the philosophical principles of wind instruments, it may, perhaps, be desirable to mention one or two instances in which sounds are produced by the vibration of columns of air. That our book may not be tedious to those for whom it is especially

written, we have blended historical details with philosophical principles; and although it may on this account be a less connected performance, it will not be the less interesting. Tubes intended for the production of sound are of various kinds; some are open at both ends, some closed, and others open at one end. We will first describe and give a short history of the flute, an instrument which is closed at one end.

The flute is the most simple of all the wind instruments. It is a tube with seven apertures, one nearly at the end, through which the performer blows, and six others, at fixed intervals, which are closed with the fingers, as occasion may require for the production of certain notes. Keys also are added for the production of the half tones. It consists of four pieces or joints, which are inserted into each other.

Although the flute is a simple, and in this country a very common musical instrument, there are few good players. It is not difficult to obtain a command of the keys, and even to perform quick passages; but it is difficult to obtain a clear and full tone, or, in other words, a good embouchure. This essential object in flute-playing is but little considered, although the greatest command of the instrument is useless without it. The flute, when well played, is a sweet instrument, and its tones approach nearer to those of the human voice than any other with which we are acquainted. A few years ago it was fashionable to play on the flute, and the ear was in almost every house tired and disgusted with the abortive efforts that were made to produce musical sounds. fashion changed, and, to the delight of all persons, the flutes of the young aspirants are now allowed to remain in their cases. The word flute has been used as applicable to many very

The