CONTENTS. i x 



BOOK II. 



ACOUSTICS. APPLICATIONS OF THE PHENOMENA 

 AND LAWS OF SOUND. 



CHAPTER. I. 



SOUND SIGNALS. 



PAGE 



I. Acoustic Signals in Navigation Bell-Buoys Speaking-Tubes The 



Invisible Woman 107 



II. The Speaking-Trumpet 110 



III. Musical Telephone for transmitting Military Orders in the Army or 



at Sea 112 



IV. Ear-Trumpets The Stethoscope . ... 113 



V. Acoustics applied to Architecture 115 



CHAPTER II. 



MUSICAL INSTRUMENTS SIMPLE INSTRUMENTS. 



I. Instruments based on the Vibrations of Rods or Plates 120 



II. Bells and Carillons or Chimes 125 



III. Drums 131 



CHAPTER III. 



STRINGED INSTRUMENTS. 



I. Ancient Stringed Instruments 135 



II. The Violin 138 



III. Bow Instruments of the Violin Family 148 



IV. The Guitar The Harp 152 



V. The Piano . . . . 1G1 



