The modes of manipulation for sending intelligence, which at various
times have been invented by Prof. Morse, are more various than any
other part of the machinery of the telegraph. A few of them will now
be described. The first method, invented as early as the year 1832,
was that of using a type, resembling saw-teeth, set up in long frames,
and made to pass under a lever, by means of machinery, at a uniform
rate, for the purpose of closing and breaking the circuit, in a manner
hereafter to be described. The following figure, 15, represents the
saw-teeth type. The top of the narrow tooth corresponds with the _dots_
of the letters, and the long tooth, with the _lines_ of the letters.
For instance, A, has one tooth for a dot, and a long tooth for a line,
which is the telegraphic letter A; then follows a space at the end of
the type, corresponding with the short space between two letters.
[Illustration: FIG. 15.]
[Illustration: FIG. 16.]
These type were set up in a cavity, made by putting two pieces of
long rules of brass plate together, side by side, with a strip of
half their width between them; so as to make the cavity sufficiently
large to receive the type. This was denominated the _port rule_, and
is represented in figure 16 by A A. Parts of the type are seen rising
above the edge of the _rule_, and below it are seen the cogs, by
which, with the wheel, V, the pinion, L, and the crank, O, the port
rule, with its type, were carried along at an uniform rate in a groove
of the frame, K, R, under the short lever, C, which has a tooth, or
cam, at its extremity. J is a support, one on each side of the frame,
for the axis of the lever, B and C, at its axis, I; _a_ and _i_ are
two brass or copper mercury cups, fastened to the frame. These cups
have the negative and positive wires soldered to them, N and P. D and
H are the ends of _one_ copper wire, bent at right angles at that
portion of it fastened to the lever, B. The ends of the copper wire are
amalgamated, and so adjusted, that when the lever is raised at C, by
the action of its cam, passing over the teeth of the type, the lever,
B, is depressed, and the wires, D and H, dip into the mercury cups,
and thus complete the connection. This plan worked well, but was too
inconvenient and unwieldy.
The second method was upon the same principle, with a more compact
arrangement. The type being put into a hopper and carried one by one
upon the periphery of a wheel, the teeth acting upon a lever in the
same manner as in the figure preceding. The wheel being horizontal.
[Illustration: FIG. 17.]
The third plan differed only in one respect, instead of the types
moving in a circle, they were made to move in a straight line. Figure
17 represents that instrument. The type were all made with small
holes through their sides, so as to correspond with the teeth of the
wheel, A, driven by clock work and weight. K is the side of the frame
containing the clock work. B is the hopper containing the types, with
their teeth outward. The hopper is inclined at an angle, so that the
type may slide down as fast as one is carried through the cavity, _a_
and _b_. C is a brass block to keep the type upright, and sliding down
with them. E and F are two small rollers, with springs (not shown)
to sustain the type, after the wheel, A, has carried them beyond its
reach. G is a lever for the same purpose as C in figure 16. D its
support, through which its axis passes. I′ is the long lever, O, of the
left side figure, to the end of which, is the bent wire in the mercury
cups, H and S, and to which are soldered the wires, P and N. T is the
spring to carry back the lever, O. F′ is one of the small rollers, and
G′ the short lever. At R may be seen a part of one of the type passing;
the tooth having the short lever upon its point, thereby connecting
the circuit at the mercury cups, H and S, by the depression of the
long lever, O. The hopper, B, may be of considerable length, and at a
less angle. When a communication is to be sent, it is set up in type,
and put in the hopper. The clock work is then put in motion, and the
wheel, A, will carry them down one by one. In this manner, the cam on
the end of the lever, G, will pass over all the teeth of the type, as
in the plan shown by figure 16.
The fourth plan was by means of keys, one for each letter and numeral.
By pressing upon any one of the keys, it wound up the clock work of the
instrument. The key being instantly released, and returning gradually
to its former position, produced the closing and breaking of the
circuit required to write its character upon the register.
The fifth plan is in some respects similar to the last, but much more
simple, and requiring less time in transmitting intelligence. Figure
18 exhibits a view of the keyed correspondent, with its clock work. A′
represents a top view of it, and B′ is a side or front view. 1 1 1 1,
of both views, represent the long cylinders of sheet brass, covered
with wood or some insulating substance, except at the black lines,
which represent the form of the letters, made of brass, appearing at
the surface of the cylinder and extending down and soldered to the
interior brass cylinder. A cross section of the cylinder is seen at D′,
of which the blank ring is the brass cylinder, and the blank openings
to the outer circle the metallic forms of the letter J, and the shaded
portion of the circle represents the insulating substance, covering
the whole surface of the cylinder, except, where the letter-forms
project from the interior. It is obvious that every letter and parts
of each letter are in metallic connection with the brass cylinder. At
each end of the cylinder is a brass head, with its metallic journal,
and the journal or arbor turns upon its centre in a brass standard,
17, secured to the vertical frame. To this standard is soldered the
copper wire, N, connected with the negative pole of the battery. There
are together thirty-seven letters and numerals upon the cylinder,
and made to correspond to the letters of the telegraphic alphabet.
To each of these, there is a separate key, directly over the letter
cylinder. Each key has its button, with its letter, A, B, C, D, &c.,
marked upon it, and beneath the button in a frame of brass, is a little
friction roller. The key is a slip of thin brass, so as to give it
the elasticity of a spring, and is secured at the thicker end by two
screws to a brass plate, extending the whole length of the cylinder,
so as to embrace the whole number of keys. This plate is also fastened
to the vertical mahogany frame. At the right hand end of the brass
plate is soldered a copper wire, leading to the positive pole of the
battery, after having made its required circuit through the coils of
the magnet, &c. It is clear, that if any one of the keys is pressed
down upon any portion of a metallic letter, that the circuit is
completed; the galvanic fluid will pass to the brass plate to which,
P, wire is soldered; thence along the plate to the spring or key; then
to the small friction roller beneath the button; then to that portion
of any letter with which it is in contact; then to the interior brass
cylinder, to the arbor; then to the brass standard, and along the
negative wire, soldered to it, to the battery. We have now to explain
in what manner, the cylinder is made to revolve, at the instant any
particular key is pressed, so that the metallic form of the letter
may pass at an uniform rate under the roller of the key; breaking and
connecting the circuit so as to write at the register, with mechanical
accuracy, the letter intended.
[Illustration: FIG. 18.]
[Illustration]
[Illustration: FIG. 19.]
4 4 is the platform upon which the parts of the instrument are
fastened. 3 3 is the vertical wooden back, or support, for the keys
and brass standard, 17. 2 is the barrel of the clock work contained
within the frames, 5 5. With the clock work, a fly is connected for
regulating its motion, and a stop, a, for holding the fly, when the
instrument is not in use; 6 is a very fine tooth wheel, on the end of
the letter cylinder; 7 is also a fine tooth wheel, on a shaft driven by
the clock train. In the front view is seen, at 9, another fine tooth
wheel, suspended upon a lever, the end of which lever is seen at 8,
figure 18, A′. 18 is a stop, in the standard, 17, to limit the return
motion of the cylinder, which also has a pin at 18, at right angles
with the former. 16 is a small weight, attached to a cord, and at its
other end, is fastened to the cylinder at _b_. The relative position
of the three fine tooth wheels, and the lever, 8, are better seen in a
section of the instrument, figure 19. The same figures represent the
same wheels as in the other views, A′ and B′. 7 is the wheel driven
by the weight and train. 6 the wheel, on the end of the cylinder, to
which motion is to be communicated, and 9 is the wheel, suspended upon
the end of the lever, 8, of which 10 is its centre. 1 1, is the brass
lettered cylinder. 11 and 13 the buttons of the two keys, one a little
in advance of the other. 14 is the spring and the two friction rollers
of the key, may be seen directly under the buttons. 15 is the stop pin.
16 the small weight and cord attached to the cylinder, to bring it back
after each operation. 4 4 is the end view of the mahogany platform.
The arrows show the direction which the wheels take, when the lever is
pressed with the thumb of the left hand at 8, so as to bring wheel 9,
up against 7 and 6, connecting the two, as shown by the dotted lines.
Wheel, 7, communicating its motion to 9, and 9 to 6, which causes the
metallic letters to pass under the rollers in the direction of the
arrow. Now, in order to use the instrument, let it be supposed a letter
is to be sent. The stop, _a_, figure 18, A′, is removed from the fly,
and the clock work is set in motion by the large weight. Then the
thumb of the left hand presses upon the _lever_, 8, at the same time,
_key_, _R_, is pressed down by the finger of the right hand, so that
the small roller comes in contact with the cylinder. At the instant
the roller touches the cylinder, the letter begins to move under the
small roller, making and breaking the circuit with mechanical accuracy.
When the letter has passed under the small roller, the thumb is taken
off the lever, 8, and the finger from the key, R. The cylinder is then
detached from its gear wheel, 9, and the weight, 16, instantly carries
it back to its former position, in readiness for the next letter.
Then the _lever_, 8, and the _key_, _E_, are pressed down at the same
instant for the next letter, and it is carried under the small roller
in the same manner as the first, which, when finished, the wheel, 9,
is suffered to fall, and the cylinder returns to its natural position
again. The same manipulation is repeated for the remaining letters of
the word.
In the following figure, 20, is represented the flat correspondent. It
somewhat resembles the keyed correspondent, but without keys or clock
work. A represents the arrangement of the letters, presenting a flat
surface. Those portions in the figure, marked by black lines and dots,
represent the letters which are made of brass. That portion which is
blank, represents ivory or some hard insulating substance, surrounding
the metal of the letters. As in the keyed correspondent, each letter
and parts of each letter extend below the ivory and are soldered to a
brass plate, the size of the whole figure, A. A sectional view of this
is seen at 1 1, which is ivory, and 2 2, the brass plate below. The
whole is fastened to a table, B. 5′ and 5′ is a brass plate, called the
guide plate, with long openings, represented by the blanks, so that
when the guide plate, 5′ 5′, is put over the form, A, each opening is
directly over its appropriate letter, and is a little longer than the
length of the letter. 4′ and 4′ is the wooden frame, to which the guide
plate is secured. The ends of this frame are seen in the sectional
figure at 4 4, and the guide plate at 5 5. The dark portions of which,
represent the partitions, and the blanks the openings. It will be
observed here that the plate, 5 5, resting upon the wooden frame 4
4, is completely insulated from the brass letter plate 1 1, and 2 2.
The blank space between them showing the separation. It is, however,
necessary that the guide plate should be connected with one pole of the
battery, and the letter plate with the other pole. For this purpose a
brass screw, F, passes up through the table, B, and through 4, into the
guide plate 5 5. The head of the screw has a small hole through it,
for passing in the end of the copper wire, G, from the battery, and a
tightening screw below, by which a perfect connection is made. At D, is
another screw, passing through the table, and into the letter plate, 2
2. To the head of this screw is also connected another copper wire, E,
extending to one of the poles of the battery.
[Illustration: FIG. 20.]
This instrument, when used, occupies the place of the key or
correspondent, in the description heretofore given of the register.
The circuit is now supposed to be complete, except, between the guide
plate, 5 5, and the letter plate, 2 2. Now, if a metallic rod, or
pencil, C, be taken, and the small end passed through one of the
openings in the shield, above the letter, its point will rest upon the
ivory; and if it be gently pressed laterally against the side of the
opening of the guide plate, at the same time a gentle pressure is given
to it upon the ivory, and then drawn in the direction of the arrow,
4′, it is obvious, that when the metallic point reaches, for instance,
the short line of letter B, the circuit will be closed; and the fluid
will pass from the battery along the wire to the screw, F, then to
the guide plate, along the plate, to the rod, thence to the metallic
short line of letter B, thence to the letter plate below, thence to the
screw, from the screw to the wire, and thence to the battery. When the
point has passed over the short metallic line, it reaches the ivory,
and the circuit is broken, then, when it comes upon the first metallic
dot, it is again completed, and in the same manner the circuit will be
completed and broken, until the point has passed over the whole of the
letter. The use of this instrument requires great uniformity of time or
speed in drawing the point over the letter form. The steel point of a
common ever-pointed pencil is frequently used in place of the pointed
rod, C.
The seventh plan is that heretofore explained as being now in use,
of which there are several varieties. This mode of writing requires
that the operator should be perfectly familiar with the alphabet, as
he is obliged to spell the word, and measure the time, required by
the various parts of each character making the letter. It might seem
difficult, yet experience has proved it to be superior to every other
method yet devised. By this method, intelligence is transmitted faster
than it can be written down by reporters; and after a little practice,
with so perfect a formation of the characters, that mechanical
accuracy can alone be compared to it. As this is the simplest in its
construction, it will doubtless supercede all the others. We will now
give its simplest form.