536 Mechanical Violin-Platjer for Acoustical Experiments, 



of movement. A weight hanging freely at the shorter end 

 of the lever balances the weight of the lath and the bow. 

 An adjustment is provided by which the bow may be held 

 obliquely so that fewer or more hairs may be made to touch 

 the strings. A vertical adjustment of the axle is also possible 

 by which it can be arranged that the hairs of the bow when 

 at rest touching the strings should be exactly parallel to the 

 cast-iron track on which the cradle of the violin slides. (This 

 is very important for the successful working of the apparatus.) 

 The block carrying the axle can also be moved parallel to the 

 strings of the violin with the aid of a screw, so that the 

 distance between the bridge and the point at which the bow 

 touches tlie string may be expeditiously altered. Finally^ 

 in order to check any movements of the lever carrying the 

 bow which would result in fluctuations of its pressure, a 

 damping arrangement is provided. A stout wire carrying- a 

 number of horizontal disks placed at intervals -bangs freely 

 from the shorter arm of the lever and dips in a beaker of 

 water or light oil. This device ensures a very smooth and 

 uniform bowing of the string, and is found to be quite suc- 

 cessful in practice. A rider can be placed at any desired 

 point on the graduated longer arm of the lever and provides 

 the necessary means of adjustment of bowing pressure. 

 The observations of the tone of the instrument are always 

 made when the violin is at or near the middle point of its 

 stroke, and quite definite values may be obtained of the 

 minimum pressure necessary under any given conditions 

 in order to elicit a sustained tone with a strongly marked 

 fundamental. 



A considerable variety of investigations can be carried out 

 with the aid of the mechanical player described above. As 

 examples may be mentioned the study of :—-(«) the relation 

 between the bowing pressure and the position of the bowed 

 point on the string ; (/>) the relation between bowing speed 

 and bowing pressure ; (c) the variation of bowing pressure 

 with pitch, and the phenomena of the wolf-note ; (d) the 

 effect of using a "mute" on the bowing pressure; (e) the 

 quantitative relation between tone-intensity and pitch for 

 different types of instrument. A detailed description of the 

 experimental results obtained on these points, and of the 

 various other applications of the mechanical player, will be 

 given in a forthcoming publication of the Indian Association 

 for the Cultivation of Science. 



Calcutta, 

 17th November, 1919. 



