( 519 ) 
circuit with three accumulators and a Konig electromagnetic tuning 
fork (Fa, = 682 v. s.). The fork was placed in a distant room. The 
tension of the string was regulated until the violin when the string 
was bowed gave a note slightly lower than the fork. The fork was 
then started and the note of the string raised by pressing it with 
the finger until no beats were heard. 
The note given out by the violin was now unmistakably Fa t . 
Now if there really were a difference of an octave between 
the note of the violin (Fa,) and the note of the string itself, the 
string ought under the influence of the electromagnet to have given 
the note Fa,. This is however impossible: an electromagnet mag¬ 
netised by a fork Fa, can produce in a string the notes Fa, Fa ,, 
Fa s etc. but never the note Fa,. The experiment was thus by itself 
sufficient to show that the note given by the violin has the same 
pitch as the note of the string itself, even when the excursions of 
the string on the two sides of its position of equilibrium are about 
equal. 
Thinking that the octave might perhaps appear, if the parallel 
motion of the bridge were damped down, we loaded the left foot 
of the bridge with our metal clamp, but even then the octave could 
not be heard. 
As the question seemed tp us of great importance we tried to 
solve it in a different more direct manner by an experiment in 
which the sound of the string was heard by itself. 
On a heavy zinc-block of 80 by 40 cms and 3 1 /, cms thick 
(Fig. 5), two metal bridges are fitted (Fig. 6) at a distance from 
eacK other of 32 1 /, cms. An a-string 0,7 to 0,75 mm thick was tied 
S f *$ 
Fig. 5. 
to a pin s, the other end being attached to a cord going over a 
pulley and a pan weighted with 6 kilogrammes. When bowed the 
string sounded a note near Ut A . The friction of the string on the 
bridges and of the cord on the pulley enabled us to slightly alter 
35 
Proceedings Royal Acad. Amsterdam. Vol. XII. 
