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