196 SEC. 6. SOUND. 



"scale, inherited by us from the Greeks, by the junction of two tetrachords. 

 For this an astronomical or theological reason is assigned, that, as there were but 

 seven planets (according to ancient supposition), and seven days in the week, 

 or quarter of the lunar month, &c., &o there should be but' seven notes in- 

 stead of eight in a musical octave. Therefore a scale of two tetrachords, 

 each of four notes, was reduced to seven, through uniting them by one note 

 common to both. Hence the intervals of our BCD E E F G A. 



757a. Indian Vina, with resonating gourds. 



IV. Chappcll, F.S.A. 



757b. Patent Comma Trumpet, producing approximately 

 correct intonation, by means of a valve, which raises the pitch the 

 interval of a comma. H. Bassett. 



757c. Marimba from Angola, on the principle of the musical 

 box. IT. Bassett. 



757d. Wooden Trumpet from Angola, made from the root 

 of a tree. H. Bassett. 



757f. Double Bass, with heavily covered fourth string, going 

 clown to C C 0. Dr. Stone. 



758. Series of Acoustic Models. M. Lancelot, Paris. 



759. Savart Violin. 



Conservatoire des Arts et Metiers, Paris. 



759a. A new Orchestral Musical Bass Instrument, with 

 concertina fingering, full tone, and expressive for part and solo 

 performance. S. F. Pichler. 



759b. Acoustical Instrument, illustrating Harmony 

 and Discord. S. F. Pichler. 



759c. Violin fitted with Tension Bars. Dr. Stone. 



759d. Viol d'amore, illustrating the principle of consonating 



springs. Dr. Stone. 



759e. Tenor Bassoon, or Altp Fagotto. Dr. Stone. 



VIII. SPECIAL COLLECTIONS. 



DETAILED LIST OF INSTRUMENTS MANUFACTURED BY 

 M. LANCELOT OF PARIS. 



Exhibited by Augustc Bel S> Co., London. 



760. Eight Pieces of Wood, giving a scale. 



761. Mouth of a Flute Pipe, showing the inside of the 

 air-chamber. 



