148 THE APPLICATIONS OF PHYSICAL FORCES. [BOOK n. 



instrument to a certain degree; they are, however, chiefly dependent 

 on the skill of the performer : the power of expression, and musical 

 feeling, added to these material qualities, constitute his genius. 



III. Bow INSTRUMENTS OF THE VIOLIN FAMILY. 



All that has just been said of the violin may be applied to all 

 instruments of the same class, of different sizes, but having almost 

 the same form and construction, externally and internally, and 

 played, like the violin, with a bow, and also by plucking the strings, 

 termed, in musical language, playing pizzicato. The tenor, alto, or 

 viola, which was also formerly called the alto-viola, is a violin of 

 rather larger dimensions, tuned to the fifth below the violin, with two 

 wire covered strings, and two ordinary gut strings producing as 

 fundamental notes, c, G, D, A. Formerly the tenor was played by 

 resting the instrument on the knees or on a table, with the same 

 bowing as the violoncello. In the present day, it is held under the 

 chin, and is used in precisely the same way as the violin. The 

 violoncello is much larger than the violin or tenor, and tuned like the 

 latter, only an octave lower. It is held between the legs of the 

 performer, so that the bow is worked in a direction contrary to its 

 action on the violin, the lower-toned strings being towards the right 

 of the performer instead of the left ; lastly, there is the contra-basso 

 or double bass still larger, the open strings of which are an octave 

 lower than the violoncello. 



It may be interesting here to notice a singular defect observable 

 in certain notes of the violoncello. In sounding a particular note on 

 the third or G string, an unpleasant jarring tone is produced, termed 

 by musicians the "wolf;" the note itself, which varies on different 

 instruments, but is usually either the E or F, being termed the " wolf 

 note." The same effect, though in a minor degree, is produced by the 

 corresponding note on the second or D string. The "wolf" is found 

 in nearly all violoncellos,' even in fine instruments by the great 

 masters, but science has hitherto failed to account satisfactorily for 

 the defect. When the " wolf note " is sounded, the whole body of the 

 instrument vibrates in an ' unusual degree, especially the belly, 

 probably on account of the elasticity of the deal of which it is 



