( M4 ) 
investigated the nature of the vibrations of tiie string, bridge, and roof of 
a sonometer as also of the air inside the sonometer. He examines both 
motions of the bridge and finds that for the same point of the bridge 
the displacement by the horizontal motion, i. e. in the direction of 
the string, is about 17 times the amplitude of the vertical motion 1 ). 
As the bridge of the sonometer is entirely different in shape from the 
bridge of the violin and the sonometer is moreover not fitted with 
a sound bar, the results of the investigation are not immediately 
applicable to the motion of the bridge of the violin. 
Savart s ) in his very important memoir on string instruments does 
not refer to the motion of the bridge. 
2. It seemed to us a priori somewhat improbable that as van 
Schaik and others suppose a comparatively massive object like the 
bridge by vibrating as a whole in its own plane about one of its 
comers should be able to follow completely the intricate motions of 
the strings and communicate them to the roof oft he violin. It seemed 
to us more probable that, as Barton found for the sonometer, both 
motions' should be taken into account. 
In order to investigate this experimentally we proceeded as follows. 
hig. 1 represents a violin-bridge manufactured by the well 
known makers Caressa & Francais of Paris. Fig. 2 shows a small 
Fig. 1. 
metal clamp which can be attached to the bridge at different points. 
In order not to damage the bridge the screw .v does not press 
l ) Phil. Mag. Ser. 6, Vol. XIII, p. 451. 
-) “Memoire sur la construction des instruments a cordes et a arctaet.” A 
reprint of this paper is to be found in: ‘Nouveau Manuel complet du luthier”, by 
Macsin and Maigne. Paris, Kbrairie encyclopedique de Roret, 1894, p. 333—398. 
