One of the causes which gives rise to induction in the telephone lines
running along the Belgian railroads is that there are so many electric
bells in the stations.
Mr. Lippens proposes as a remedy for the trouble a slight modification
of the vibrating bell of his invention so as to exclude from the line
the extra currents from the bell.
In one of the styles (Fig. 1) a spring, R, is attached at T to a fixed
metallic rod, and presses against the rod, T¹. The current enters
through the terminal, B, traverses the bobbins, passes through T,
through the spring, through T¹, and makes its exit through the other
terminal. The armature is attracted, and the point, P, fixed thereto
draws back the spring from the rod, T¹, and interrupts the current;
but, at the moment at which the point touches the spring, and before
the latter has been detached from the rod, T¹, the electro-magnet
becomes included in a short circuit, and the line current, instead of
passing through the bobbins for a very short time, passes through the
wire, T, the armature, and the rod, T¹, so that the extra current is
no longer sent into the line.
[Illustration: FIG. 1.]
In another style (Fig. 2) the current is not interrupted at all, but
enters through the terminal, B, traverses the bobbins, and goes
through C to the terminal, B.
[Illustration: Fig. 2.]
As soon as the armature is attracted, the spring, R, which is fixed to
it presses against the fixed metallic rod, T, and thus gives the
electricity a shorter travel than it would take by preference. The
current ceases, then, to pass through the bobbins, demagnetization
occurs, and the spring that holds the armature separates anew. The
current now passes for a second time into the bobbins and produces a
new action, and so on. There is no longer, then, any interruption of
the current, and the motions of the hammer are brought about by the
change in direction of the current, which alternately traverses and
leaves the bobbins.
In a communication that he has addressed to us on the subject of these
bells, Mr. Lippens adds a few details in regard to the mode of
applying the ground pile to micro-telephone stations.
Being given any two stations, he puts into the ground at the first a
copper plate, and at the second a zinc one, and connects the two by a
line wire provided with two vibrating bells and two telephone
apparatus. The earth current suffices to actuate the bells, but, in
order to effect a call, the inventor is obliged to run them
continuously and to interrupt them at the moment at which he wishes to
communicate. The correspondent is then notified through the cessation
of noise in the bells, and the two call-apparatus are thrown out of
the circuit by the play of the commutator, and are replaced by the
micro-telephone apparatus.
It is certainly impracticable to allow vibrating bells to ring
continuously in this manner. The ground pile would, at the most, be
only admissible in cases where the call, having to be made from only
one of the stations, might be effected by a closing of the
circuit.--_La Lumiere Electrique_.
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The advantage of lighting vessels by electricity was shown when the
steamer Carolina, of the old Bay Line between Baltimore and Norfolk,
ran into the British steamship Riversdale in a dense fog off Cedar
Point, on Chesapeake Bay. The electric lights of the Carolina were
extinguished only in the damaged part of the boat, and her officers
think that if she had been lighted in any other way, a conflagration
would have followed the collision.
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