ACOUSTICS. 



CHAPTER I. 



PERCUSSION. THE STRING AND REED. THE TRUMPET. EAR- 

 TRUMPET. STETHOSCOPE. 



The Science of Sound. Rhythmical Vibrations. The Drum. Primitive Drums. 

 The Solid and Hollow Lo<?. The Bass Drum and Kettle-drum. African 

 Drums. Gnostic Gerns and the Ashanti Drum. Tympanum, or Drum of 

 the Human Ear, and its Mechanism. An artificial Tymp-mum. The 

 String. The Bow and the Harp. The Harpsichord and the Zither. The 

 Bow and the Violin. The Cricket. The Vibrator, or Reed. The Jew's 

 Harp and Harmonium. The Cicada and its Song. Harmonica upon Strings. 

 The JEolian Harp. Harmonics upon the Trumpet. The Trombone. 

 Trachea of the Swan. The Ear-trumpet. The Sea-shell. The Stethoscope. 

 Savage Food. The Aye-aye. The Siren and its Uses. Echo and Whis- 

 pering Gallery. 



IN a work of this nature it would be absolutely impossible, 

 not to say out of place, to give an account of so elaborate 

 a subject as ACOUSTICS, i.e. the science of Sound. Suffice it to 

 say, that all sounds are produced by the vibration of air, and 

 that the fewer vibrations, the lower is the sound, and vice 

 versa. 



When such vibrations are produced regularly, they form 

 Musical sounds, but, if irregularly, the sounds can be only 

 distinguished under the term of Noise. The earliest germ of 

 music lies in certain savage races, who, as long as they cau 

 maintain a rhythmical beat on any resonant substance, do not 

 particularly care what it is. A hollow tree is a splendid instru- 

 ment in their opinion, but, if this cannot be had, a dry log of 

 wood will answer the same purpose. 



Some tribes, more ingenious than others, cut a deep groove 

 upon the upper surface of a log, hollow it through this groove, 

 aud then hammer away at it to their hearts' content. The 



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