In this
case, when two persons are holding the handles, and have their ears
applied, one against the other, if a sheet of paper be interposed,
airs or words will be heard to proceed therefrom. Finally, it has been
found possible to entirely suppress the paper, or dielectric, and to
hear directly, by simply interposing the auditor or auditors in the
circuit. One of the most curious forms of the experiment is the one
shown in Fig. 2. Here a third person, C, hears the hands of A and B
speak when a circuit is formed by means of three persons, A, B, and C,
the two former, A and B, each holding one of the wires of the circuit
and applying his free hand to the ear of C. Although the experiment is
one that requires entire silence, and could not on that account be
performed at the laboratory, a sort of telephonic chain can be formed
in which five or six persons may hear at the same time. A, putting his
hand on the ear of B, the latter putting his to that of C, and so on
up to the last person, who closes the circuit by grasping one of the
handles, the other one being held by A.
[Illustration: EXPERIMENT ON TELEPHONIC TRANSMISSION WITHOUT
RECEIVING APPARATUS.]
It is difficult in the present state of science to explain very
clearly how these telephonic transmissions are effected without a
receiver. All that we can conclude from it so far is that the ear is
an instrument of incomparable delicacy and of exquisite sensitiveness,
since it perceives vibrations in which the energy developer,
particularly in the telephonic chain, is exceedingly feeble.
Pages:
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104