ON MUSICAL INSTRUMENTS. 311 



n all these, the immediate force of the sound of the strings 

 is increased by means of a sounding board, which appears to be agitated by 

 their motion, and to act more powerfully on the air than the strings could 

 do alone. 



In the harp, the sound is produced by inflecting the string with the finger, 

 and suffering it to return to its place. The lyre of the ancients differed 

 from the harp only in its form and compass, except that the performer 

 sometimes used a plectrum, which was a small instrument, made of ivory, 

 or some other substance, for striking the strings. Each note in the harp 

 has separate string ; and in the Welsh harp there are two strings to each 

 note of the principal scale, with an intermediate row for the semitones ; but 

 in the pedal harp, the half notes are formed by pressing pins against the 

 strings, so as to shorten their effective length. Instead of this method, an 

 attempt has lately been made to produce the semitones by changing the 

 tension of the strings, which is said to have succeeded tolerably well, al- 

 though it appears at first sight somewhat unpromising. 



In the harpsichord, and in the spinet, which is a small harpsichord, the 

 quill acts like the finger in the harp, or the plectrum in the lyre, and it is 

 fixed to the jack by a joint with a spring, allowing it without difficulty to 

 repass the string, which is here of metal. Sometimes leather is used instead 

 of quills ; and this serves to make the tone more mellow, but less powerful. 

 Besides two strings in unison, for each note, the harpsichord has generally 

 a third which is an octave above them. Different modifications of the tone 

 are sometimes produced by striking the wire in different parts, by bringing 

 soft leather loosely into contact with its fixed extremity, and by some other 

 means. When the finger is removed from the key, a damper of cloth falls 

 on the string, and destroys its motion. In all instruments of this kind, the 

 perfection of the tone depends much on the construction and situation of 

 the sounding board : it is usually made of thin deal wood, strengthened at 

 different parts by thicker pieces fixed below it. 



In the pianoforte, the sound is produced by a blow of a hammer, raised 

 by a lever, which is as much detached from it as possible. The dulcimer, 

 or hackbrett of the Germans, is also made to sound by the percussion of 

 hammers, but they are simply held in the hand of the performer. 



The clavichord, the clavier of the Germans, differs from other keyed 

 instruments in the manner in which the length of the string is determined ; 

 it is attached at one end to a bridge, and at the other to a pin or screw as 

 usual ; but the effective length is terminated on one side by the bridge, and 

 on the other by a flat wire projecting from the end of the key, which strikes 

 the string, and at the same time serves as a temporary bridge as long as the 

 sound continues : the remaining portion of the string is prevented from 

 sounding by being in contact with a strip of cloth, which also stops the 

 whole vibration as soon as the hammer falls. The instrument is capable of 

 great delicacy and neatness of expression, but it is deficient in force. The 

 guitar is generally played with the fingers, like a harp ; but each string is 

 made to serve for several notes, by means of frets, or cross wires, fixed to 

 the finger board, on which it is pressed down by the other hand. But in 

 the pianoforte guitar, hammers are interposed between the fingers and the 



