498 TRANSACTIONS OF THE 



Mr. Howe also treated of the harp and violin, and spoke of their excel- 

 lence as consisting in the ease with which the performer produced any 

 interval in true pitch, by lengthening or shortening the string, by sliding 

 the finger up or down upon it. In this particular the piano is peculiarly 

 deficient. 



After Mr. Howe's paper, a neat little apparatus was shown, by Mr.- John- 

 son, which produced a clear, ringing tone, by the impact of two columns of 

 air, one upon the other. It originated from Mr. Stevens' gas burner 

 giving a musical tone, when the outflow of gas is too strong for economical 

 consumption, 



Mr. S. D. Tillman remarked that the interesting paper of Mr. Howe 

 related principally to the quality of musical notes, particularly those pro- 

 duced by the Boehm flute. As the subject of musical instruments embraced 

 all kinds, it necessarily included that of temperament, which has always 

 been regarded as a mysterious subject. 



The sensation of sound is caused by vibrations or pulsations of the air ; 

 when the pulsations occur at irregular intervals the sound is called " noise." 

 When at regular intervals, " music," or "musical sound. 



The "pitch" of a musical sound depends on the number of pulsations of 

 the air which are produced in a given time; the "loudness," upon the 

 mechanical force with which they are produced, and the " quality," upon 

 the smoothness of the wave. The Boehm flute gives tones remarkable for 

 their smoothness ; the clarionet those of the opposite character. 



The string of the piano always gives the same tone, giving it loudest 

 ■when first struck, then gradually dying off, the vibrations being isochronous, 

 though of unequal amplitude. It being important to have a standard pitch, 

 the French have lately adopted A, which conforms to 822 vibrations for the 

 middle C, between the bass and treble clefs. 812 vibrations would be 

 better, and the speaker was glad to find that Sir John Hersehel had lately 

 ■written an interesting letter, in which he advocates the latter. In selecting 

 a standard, the barometer is supposed at 30 inches, and Fahrenheit's 

 thermometer at G2 deg. The lowest C which can be heard has, according 

 to this standard, 16 vibrations in one second of time, the first octave 

 C above it has double the number of vibrations, 32 ; the nest C above has 

 64; the next above. 128; the next, 256; and the next, or middle C, has 

 512. To get the octave of any sound made by a pipe or string, we reduce 

 the pipe or string one half in length, which produces double the vibrations. 

 The raonochord is a single string on which the whole series of sounds can 

 be obtained by measurements. If 1 represent the whole string, ^ will re- 

 present its octave, j will give the Jif I h, which is the next best chord to the 

 octave. In this way we get a series of fractions which represent all the 

 notes, but these sounds all belong to the original key. If the tonic or key- 

 note is changed, the original true notes will be found untrue, because the 

 ratio between the first and second notes is different from that between the 

 second and third ; one is a major tone and the other a minor tone, while 



