L 535 ] 



XLTX. Notices respecting New Books. 



YlBRATlONS OF BOWED INSTRUMENTS. 



On the. Mechanical Theory of the Vibrations of Bowed Strings and 

 of Musical Instruments of the Violin Family, with Experimental 

 Verification of the Results : Part I. By C. V. Kaman, M.A., 

 Life-Member and Vice-President, Indian Association for the 

 Cultivation of Science. Calcutta : The Indian Association for 

 the Cultivation of Science, 1918. Pp. hi + 158. Price 3s. 4d. 



r FHE investigations, mathematical and experimental, here re- 

 -■- corded form a happy alternating blend and constitute a 

 notable advance in this interesting subject. 



Heimhollz, by his vibration microscope, obtained experimental 

 data as to the motion of: a well-bowed string, and upon this 

 built up his theory. He also surmised that the bowed point 

 moved forward at the speed of the bow and returned quicker. 

 Among many other results obtained in the present work this 

 surmise is shown to be true for ideal conditions. In other cases 

 it may be approached but not reached. 



After Helmholtz came the work of F. Krigar-Menzel and 

 A. Baps, who directly photographed on a film the displacement- 

 time curves of the vibrations of bowed strings under a variety of 

 conditions. More recently E. H. Barton and his students worked 

 upon the vibrations of bowed and plucked strings on the mono* 

 chord and violin, obtaining photographically simultaneous diss 

 placement-time curves of string and some associated part of the 

 instrument, bridge, belly, &c. 



The present work strikes a new note in that the vibrations of 

 the string under the forcing of the bow and coupled with the 

 yielding of the bridge are all treated by the appropriate differential 

 equations which are solved and discussed. 



The wolf-note pitch "of the 'cello is specially dealt with and 

 simultaneous curves obtained for string and bridge showing 

 cyclical alternations of amplitude. The theory of the bridge 

 motion, in general and when muted, is also tested by experimental 

 curves with the bridge loaded in various ways. 



A kinematical theory of the bow's action is worked out, which 

 leads to the possibility of vibrations represented by graphs con- 

 sisting of two-step zig-zags, or more complicated forms of similar 

 types. 



Bowing under various conditions as to pressure and speed are 

 treated. 



Besides 28 text-figures, the work contains 26 full-page plates 

 giving excellent photographic reproductions of vibration curves 

 many of them being of striking beauty and interest. 



