630 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



and gave forth the sound after his voice was silent. But it responds only 

 to the note it would make on being struck by the finger. These are called 

 sympathetic vibrations. Now the human ear receives all sounds, but the 

 tympanum must report the precise number of vibrations which the air has 

 given; it seems, therefore, apparent that the same person could not regard 

 the same sound as different in pitch when hoard first by one ear, and then 

 by the other. 



Mr. Garvey said he was not convinced by the argument just made, be- 

 cause sympathetic vibrations were not confined to the number making a 

 single sound; for the octave, third and fifth of that sound were also gener- 

 ated, and in many cases were loud enough to be heard. 



A Standard Diapason. 



The Chairman said it might not be out of place to allude to an interest- 

 ing fact with regard to the diapason. Many people suppose, that as we 

 have an abundance of tuning-forks, we must have a permanent standard of 

 pitch. But the existence of church bells several hundred years old, tuned 

 at first to certain letters, prove by their present sounds that the standard 

 pitch has been raised considerably. Italian concert pitch has always 

 been higher than that in ordinary use. The cause of the gradual ascent 

 of the diapason is, probably, owing to the fact that the violin, the leading 

 instrument, is tuned by fifths; and that in modulation by true fifths, which 

 can only be made by stringed instruments of the violin class, or wind in- 

 struments having sliding tubes like the trombone, there is a constant ten- 

 dency to overlap a true octave. Twelve-fifths measured upward exceeds 

 seven octaves just the musical interval called a comma. The isotonic tem- 

 perament of all instruments having twelve fixed sounds within the octave, 

 like the flute and piano, require that E and A should be more acute than 

 the true notes of the natural scale distinguished by these two letters. 

 Conversations with the distinguished composer Wallace has confirmed this 

 opinion. The musical world has not yet adopted a standard diapason. 

 France, always foremost in metrical reforms, several years since fixed the 

 pitch of A at 870 vibrations per second, equivalent to 522 vibrations for the 

 middle C. Doubling this number will give the consecutive octaves above, 

 and halving it the octaves below. It will be perceived that fractions must 

 be introduced below 261 vibrations, therefore many scientists, among them 

 Sir John Herschel, have recommended the adoption of the pitch produced 

 by 512 vibrations per second as the middle C. It is the ninth octave of an 

 imaginary sound having one vibration per second. The fourth octave is 

 the lowest which makes such impression on the sense of hearing as to give 

 to the mind a perception of sound. 



The Paixhan Gun. 



Capt. Maynard desired to correct a statement made at the last meeting, 

 that the Kussians inaugurated horizontal shell-firing. The fact is that the 

 system is entirely American. The gun for horizontal shell-firing was in- 

 vented by Col. Bomford during the administration of Jefferson, which he 

 desired to call the Jeffersoniad, but as the President was not a military 



