INDEXEL 
THE 
LONDON, EDINBURGH, ann DUBLIN 
PHILOSOPHICAL MAGAZINE 
AND 
JOURNAL OF SCIENCE: 
[SIXTH SERIES.] 
NOVEMBER 1904. 
LVI. On the Vibrations of Strings excited by Plucking and 
by Resonance. By W. B. Morton, M.A., and_T. B. 
Vinycome, J.A., Queen’s College, Belfast*. 
[Plate XVI.] 
Introduction. 
PHOTOGRAPHIC method of recording the motion of 
a particular point on a vibrating string was devised by 
Krigar-Menzel and Raps+ in 1891. It consists in forming, 
in the plane of vibration of the string, a real image of a 
brightly illuminated slit, and photographing this on a moving 
plate. The final image of the slit is thus broken by a dark 
point where the string crosses it. The combination of the 
up-and-down motion of the string and horizontal motion of 
the plate causes this point to trace a wavy line, which is 
the graph of displacement against time for the chosen point 
of the string. The mode of vibration can thus be compared 
with theory. 
The method has been applied by its inventors to the exami- 
nation of bowed } and of plucked{ strings; by Kaufmann § 
to pianoforte strings; and by Klinkert || to strings kept in 
vibration by electromagnetic means. | 
Our original object was to obtain a record of the initial 
stages in the motion of a string set in sympathetic vibration 
* Communicated by the Authors. 
+ Krigar-Menzel and Raps, Wied. Anz. vol. xliv. p. 623 (1891). 
t Krigar-Menzel and Raps, zdzd. vol. 1. p. 444 (18983). 
§ Kaufmann, zd7d. vol. liv. p. 675 (1895). 
|| Klinkert, 2b¢d. vol. Ixv. p. 849 (1898). 
Phil. Mag. 8. 6. Vol. 8. No. 47. Nov. 1904, 28 
