Telephonic communication between the Opera and the Exhibition of
Electricity is obtained by means of twenty conducting wires, which are
divided between two halls hung with carpets to deaden external noises.
We represent in the accompanying engraving one of these halls, and the
one which is lighted by the Lane-Fox system of lamps. As may be seen,
there are affixed against the hangings, all around the room, long
mahogany boards, to which are fastened about twenty small tablets
provided with hooks, from which are suspended the telephones. The
latter are connected with the underground conductors by extensible
wires which project from the wooden wainscot of which we have just
spoken, so that it is very easy for the auditors to put the telephones
to their ears.
[Illustration: ONE OF THE TELEPHONIC HALLS AT THE ELECTRICAL
EXHIBITION.]
As the telephones are connected in series of eight with the same
couple of microphone transmitters, and as each of these transmitting
couples occupies a different position on the stage, it results that
the effects are not the same at different points of each hall. Those
telephones, for example, which correspond with the foot-lights of the
theater are more affected by the sounds of the large instnuments of
the orchestra than those which occupy the middle of the foot-lights;
but, as an offset to this, the latter are affected by the voice of the
prompter. In order to equalize the effects as much as possible, Mr.
Ader has arranged it so that the two transmitters of each series shall
be placed under conditions that are diametrically opposite. Thus, the
transmitter at the end of the foot-lights, on the left side,
corresponds with the transmitter of the series to the right, nearest
to the middle of the stage; and the arrangement is the same, but in an
inverse direction, for the transmitter at the end of the foot-lights
to the right. But the series which produces the best effects is, as
may be readily comprehended, that which corresponds with the
transmitters occupying the middle of the right and left rows. These
considerations easily explain the different opinions expressed by
certain auditors in relation to the predominant sounds that they have
heard, and why it is that some of them who have listened in different
parts of the same hall have not had the same impressions. Naturally,
the fault has beeen laid to the telephones; but, although these may
vary in quality, it is more particularly to the arrangement of the
transmitters on the stage that are to be attributed the differences
that are noted.
As the Opera does not give representations every day, Mr. Ader has had
the idea of occupying the attention of the public on Tuesday,
Thursday, Saturday, and Sunday with the telephonic effects of
flourishes of trumpets, which imitate pretty well the effects of
French horns. These experiments have taken place in the hall in which
is installed the little theater, and we must really say that in the
effects produced French horns count for nothing.--_La Lumiere
Electrique._
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