This, as we have said, is the most simple form of the key, or
correspondent. It is a modification of that shown at figure 11. The
following figure, 21, represents a key, where the lever is taken
advantage of to make a more perfect connection, with less application
of power. A key of the above form has been used during the past winter
for reporting the proceedings of Congress, and has been found to
operate with ease, with certainty, and with great rapidity. A A is the
block or table to which the parts are secured. E represents the anvil
block. J the anvil, screwed into the block, both of brass. B is another
block, for the stop anvil, K, and the standard for the axis of the
lever C. L is the hammer, and is screwed into the lever, projecting
downward at V, almost in contact with the anvil, J. R is another screw
of the same kind, but in contact with the anvil, K, when the lever C
is not pressed upon. Under the head of each of these two screws, are
tightening screws, which permanently secure the two hammers, to any
adjusted position required for the easy manipulation of the lever, C.
D is a spring which sustains the arm of the key up, preventing the
hammer, L, from making contact with the anvil, J, when not in use. G is
a screw connecting with the brass block, B, and F a screw connecting
with the block, E. To these screws the two wires, I and H, of the
battery are connected. Now, in order to put it in operation, it is
necessary to bring the hammer, V, in contact with the anvil, J, for
so long a time, and at such regular intervals as are required by the
particular letters of the communication. When the key is pressed down,
the fluid passes from the battery to the wire, H, then to the screw, G,
then to the block, B, then to the lever, C, at the axis, S, then to its
metallic anvil, J, then to its screw, F, then to the wire, I, and so to
the battery.
[Illustration: FIG. 21.]
_The circuit of the Electro Magnet, closed and broken
by the movement of the lever itself, acted upon by
the Electro Magnet. Showing the rapidity with which
it is possible to close and break the circuit._
In order to give some idea of the rapidity with which the circuit
may be closed and broken, and answered by the motion of the lever,
a figure, 22, is here introduced to explain its construction and
arrangement. The platform is shown at T, and the upright at S, to
which the coils of the electro magnet, A, are secured by a bolt with
its thumb-nut, E. D a projecting prong of the soft iron, and C the
armature attached to the metallic lever, B, which has its axis or
centre of motion at K, in the same manner as the electro magnet of the
register; R being the standard through which the screws pass. O is the
steel spring secured to R, by a plate, U, upon it, and the screw, N.
L and M are adjusting screws, for the purpose of confining the motion
of the lever, B, within a certain limit. P is a wire with an eye at
the top, through which the end of the steel spring passes, with a hook
at the other end, passing through the lever. The wire, Q, from one of
the coils is connected with the plate, U, at the top of the standard,
R. As the standard, R, is of brass, the plate U, the axis of the lever
of steel, and the lever, B, of brass, all of them being metals, and
conductors of the galvanic fluid, they are made in this arrangement to
serve as conductors. I is the wire proceeding from the other coil, and
is extended to one pole of the battery. The wire, H, coming from the
other pole, is soldered to the metallic spring, J, which is secured to
the upright, S, by means of the adjusting thumb screws, F and G. This
spring is extended to J, where it is in contact with the lever, B. We
have now a complete circuit. Commencing at I, which is connected with
one pole of the battery, from thence it goes to the first coil; then to
the second; then by Q to U, the plate; then to the standard, R; then to
the steel screw, K; then to the steel axis; and then to the lever to
the point, J; where it takes the spring to H, the wire running to the
mercury cup of the other pole of the battery.
[Illustration: FIG. 22.]
The battery being now in action, the fluid flies its circuit; D becomes
a powerful magnet, attracting C to it, which draws the lever down in
the direction of the arrow, X. But since B and J are a part of the
circuit at V, and since, by the downward motion at X, and the upward
motion at V, the circuit is broken at J, the consequence is, that the
current must cease to pass, and D can no longer be a magnet. Hence
the lever at V returns, coming again in contact with J. Instantly the
fluid again passes and the lever at V separates from J. Again the fluid
ceases to pass, and the lever again returns. By this arrangement, then,
the lever breaks and closes the circuit, and it does it in the best
possible manner to show how rapidly the magnet can be made and unmade.
When its parts are well adjusted, its vibrations are so quick that no
part of the lever is distinctly seen. It appears bounded in size by the
limits of its movement up and down, and the motion is so rapid as to
produce a humming noise, sometimes varying the notes to a sharp key. In
this way it will continue to operate so long as the battery is applied.
We infer from this, the almost inconceivable rapidity, with which
it is possible to manipulate at the key of the register in sending
intelligence, far surpassing that of the most expert operator. This
arrangement of the electrome, was devised by Mr. Vail in the summer of
1843.[8]
[8] See Silliman’s Journal, vol. 35, 1839, pages 258-267.