86 Mr» Wheatstone on Sound, [Aug. 



elastic plates, this eminent philosopher found the particles not 

 only repulsed to the nodal hnes, but at the same time accumu- 

 lated in small parcels, on and near the centres of vibration ; 

 these appearances he presumed to indicate more minute vibra- 

 tions, which were the causes of the quahty of the sound : sub- 

 sequently he confirmed his opinion, by observing the crispations 

 of water, or alcohol, on similar plates, and showed that the 

 same minute vibrations must take place in the transmitting 

 medium, as they were equally produced in a surface of water, 

 •when the sounding plate was dipped into a mass of this fluid. 

 These experiments were inserted in Lieber's History of Natural 

 Philosophy, 1813. 



Mectilineal Transmission of Sound. 



As the laws of the communication of the phonic vibrations are 

 more evident in linear conductors, I shall confine the present 

 article to a summary of their principal phenomena. 



In my first experiments on this subject, I placed a tuning 

 fork, or a chord extended on a bow, on the extremity of a glass, 

 or metallic rod, five feet in length, communicating with a sound- 

 ing board ; the sound was heard as instantaneously as when the 

 fork was in immediate contact, and it immediately ceased when 

 the rod was removed from the sounding board, or the fork from 

 the rod. From this it is evident that the vibrations, inaudible 

 in their transmission, being multiplied by meeting with a sono- 

 rous body, become very sensibly heard. Pursuing my investiga- 

 tions on this subject, I have discovered means for transmitting, 

 through rods of much greater lengths and of very inconsiderable 

 thicknesses, the sounds of all musical instruments dependant on 

 the vibrations ofsoUd bodies, and of many descriptions of wind 

 instruments. It is astonishing how all the varieties of tune, 

 quality, and audibility, and all the combinations of harmony, are 

 thus transmitted unimpaired, and again rendered audible by 

 communication with an appropriate receiver. One of the prac- 

 tical applications of this discovery has been exhibited in London 

 for about two years under the appellation of " The Enchanted 

 Lyre." So perfect was the illusion in this instance from the 

 intense vibratory state of the reciprocating instrument, and from 

 the interception of the sounds of the distant exciting one, that 

 it was universally imagined to be one of the highest efforts of 

 ingenuity in musical mechanism. The details of the extensive 

 modifications of which this invention is susceptible, I shall 

 reserve for a future communication ; the external appearance 

 and effects of the individual application above-mentioned have 

 been described in the principal periodicaljournals. 



The transmission of the vibrations through any communicat- 

 ing medium as well as through linear conductors is attended by 

 peculiar phenomena; pulses are formed similar to those in lon- 

 gitudinal phonics, and consequently the centres of vibration and 



