The electro magnet is the basis upon which the whole invention rests
in its present construction; without it, it would entirely fail. As
it is of so much importance, a detailed account will be given of the
construction of the electro magnet, as used for telegraphic purposes.
A bar of soft iron, of the purest and best quality, is taken and made
into the form presented in figure 5, which consists of four parts,
viz. A F and A F are the two legs or prongs of the magnet,[2] of a
rounded form, and bent at the top, approaching each other towards the
centre, where the ends of each prong, without touching, turn up, and
present flat, smooth and clean surfaces, level with each other at F F.
The other end of these prongs or legs is turned smaller than the body,
on the end of which is a screw and nut, C C. These ends pass through
a plate of iron, B, of the same quality, at I and I, until they rest
upon the plate at the shoulder produced by turning them smaller. They
are then both permanently secured to the plate, B, by the nuts, C C,
and the whole becomes as one piece. This arrangement is made for the
purpose of putting on the coils or taking them off with facility. The
form most common for electro magnets is that of the horse-shoe; and is
simply a bar of iron bent in that form. E represents a small flat plate
of soft iron, sufficiently large to cover the faces of the two prongs,
F and F, presenting on its under side a surface clean and smooth, and
parallel with the faces, F and F.
[2] The term _magnet_, here, is synonymously used with the iron for
the magnet, as the simple iron is not a magnet, except when subjected
to the action of the battery through the helices of wire around it.
It would confuse the reader, if this distinction be not kept in view.
_Permanent magnets_ are those which retain their magnetism when once
they are charged. They are always made of steel, and usually bent in
the form of a horse-shoe. Sometimes they are of a single plate of
that form, and others are constructed with many plates, side by side,
fastened together so as to present a compact magnet of the same form.
They are distinguished from _Electro Magnets_ from the fact, that the
soft iron of the latter depends upon the influence of the galvanic
fluid for its magnetism, and retains it only so long as the soft iron
is under its influence, while the former, when once submitted to the
influence of the galvanic fluid, retain their magnetism permanently.
[Illustration: FIG. 5.]
The coils or helices of wire, which surround the prongs, A A, necessary
to complete the electro magnet, consist of many turns of wire, first
running side by side, covering the form upon which the spiral is made,
until the desired length of the coil is obtained; the wire is then
turned back, and wound upon the first spiral, covering it, until the
other end of the coil is reached, where the winding began; then again
mounting upon the second spiral, covers it, and in the same manner
it is wound back and forth, until the required size of the coil is
attained.
[Illustration: FIG. 6.]
The coil is wound upon a form of the size (or a little larger) of the
legs of the magnet, and when the coil is completed, the form is taken
out, leaving an opening in the centre, B, into which the prongs may
freely pass. Figure 6 represents a coil constructed in the manner
described. A and A are the two ends of wire which are brought out from
the coils. The one proceeds from the centre of the coil, and the other
from the outside. C and C are circular wooden heads, on each end of
the coil, and fastened to it by binding wire, running from one head
to the other, around the coil. The wire used in constructing it, as
heretofore mentioned, is covered in the same manner as bonnet wire, and
saturated or varnished with gum shellac. This preparation is necessary,
in order to prevent a metallic contact of the wires with each other.
Such a contact of some of the wires with others encircling the iron
prong, would either weaken or altogether destroy the effect intended
by their many turns. If the wires were bare, instead of being covered,
the galvanic fluid, when applied to the two ends, A and A, instead
of passing through the whole length of the wire in the coil as its
conductor, would pass laterally through it as a mass of copper, in
the shortest direction it could take. For this reason, they require a
careful and most perfect insulation. Two coils are thus prepared for
each magnet, one for each prong, A and A, figure 5.
[Illustration: FIG. 7.]
Figure 7 exhibits a view of the magnet; figure 5, with its two coils, H
and H, placed upon the prongs. Those parts of the magnet, not concealed
by the coils, are lettered as in figure 5, and correspond with its
description. P represents the wire connecting the coil H with H, and A
and A the ends of the wires leaving the coils.
We now proceed to explain the manner by which the magnet is secured
upon a frame, and the arrangement of the armature, E, figure 7, upon
a lever, so that the motion peculiar for telegraphic writing may be
shown.
[Illustration: FIG. 8.]
Figure 8 exhibits, in perspective, a view of the electro magnet and the
pen lever, in a condition to show the effect of the galvanic battery
upon the prongs of the magnet, F and F, and the armature, D, and the
movement of the pen lever to which the electro magnet is secured. A
bolt, upon the end of which is a head or shoulder, passes through the
centre of the upright block, C, and between the coils, H and H, and
also through the brass brace, O, projecting a little beyond it, with a
screw cut upon its end. The thumb-nut, P, fitted to it, is then put on,
and the whole firmly held by screwing the thumb-nut as far as possible.
F and F are the faces of the iron prongs, as shown in figure 7,
presenting their flat surface to the armature, D. L is the pen lever,
suspended upon steel points, as its axis, which pass through its side
at X, and soldered to it. Each end of this steel centre is tapered so
as to form a sharp and delicate point or pivot. E is a screw, passing
through the side of the brass standard, G, and presenting at its end
a sunken centre, the reverse of the steel pivot point at X. There is
also another screw, similar to E, passing through the other side of the
standard at G′, with a sunken centre in its end. By the extremities
of these two screws, to which the tapered ends of the steel centre is
fitted, the pen lever is suspended, so as delicately to move up and
down, as shown by the direction of the arrow. The brass standard, G,
is secured to the upright block, C. D is the armature, soldered to
the end of the brass pen lever, L, separated from the faces of the
magnet, F and F, about the eighth of an inch. W is a yoke, secured
to the lever by a screw, and which admits through its lower part the
steel wire spring, M M, for the purpose of bringing down the lever
when not acted upon by the electro magnet. The spring is secured to a
brass standard at the top, represented by N. R represents the three
steel points of the pen,[3] which mark upon the paper the telegraphic
characters; each of which strike into its own appropriate groove in the
steel roller, S. T and T are the flanges of the steel roller, S, and
which confine the paper as it passes between the pen points, R, and the
steel roller, S, described more fully hereafter. J and I are two screws
in the horizontal cross bar attached to the standard, G, and are used
for the purpose of adjusting and limiting the pen lever in its movement
upward and downward; the one to prevent the pen points from striking
too deeply into the paper and tearing it, and the other to prevent the
armature from receding too far from the faces of the electro magnet,
and beyond its attraction, when it is a magnet. K is the connecting
wire of the two coils H and H. A and B show the ends of the wire, one
coming from each coil and passing through the stand, and seen below at
_a_ and _b_.
[3] One marking point will suffice.
Having explained this arrangement of the electro magnet, the pen lever,
and the battery; the effect of the latter upon the former will now be
described. Let one of the wires from the coils, figure 8,—_a_, for
instance, be extended so far, that it can conveniently and securely
be connected with the mercury cup, N, figure 4, of that pole of the
battery. Then take the wire _b_, figure 8, and extend it also to a
convenient length, so as to be freely handled, and connect it with the
mercury cup, P, figure 4, of the other pole of the battery. It will be
found at the instant the connection is made, that the lever, L, figure
8, will fly up in the direction of the arrow at W. The iron prongs in
the centre of the coils, H and H, which were before perfectly free
from any attractive power, have now become powerfully magnetic by the
inductive influence of the galvanic current following the circuitous
turns of the wire around the iron, so that now the electro magnet
is capable of sustaining twenty or twenty-five pounds weight. This
magnetic power concentrated in the faces of the electro magnet, F
and F, attracts to it the armature or small iron, D, drawing the pen
lever down on that side of its axis, and producing a reverse motion on
the other side at L. Now take out the wire _b_ from the mercury cup,
and in an instant its magnetism is gone, and the lever, L, falls by
the action of the spring, M. If the circuit is closed a second time,
the lever again flies up; and if immediately broken, falls. In this
manner it will continue to operate in perfect obedience to the closing
or breaking of the circuit. If the circuit is closed and broken in
rapid succession, the lever obeys and exhibits a constant and rapid
vibration. If the circuit is closed and then broken after a short
interval, the lever will remain up the same length of time, the circuit
is closed, and falls upon its being broken. Whatever may be the time
the circuit is broken, the lever will remain up for the same length
of time, and whatever may be the time it continues broken, the lever
will remain down for the same time. Suppose the magnet is separated
at the distance of one mile from the battery; upon manipulating at
the battery, at that distance, in the manner just described, the same
vibratory motion is produced in all its varieties, as when they were
removed only a short distance. Separate them 10 miles, and still the
same mysterious fluid is obedient to the pleasure of the operator in
producing the desired motion of the pen lever. If they were separated
at distances of 100 or 1000 or 100,000 miles apart, the lever would
doubtless obey the manipulations of the operator, as readily as if only
distant a few feet. Here is exhibited the principle upon which Morse’s
Electro Magnetic Telegraph is based, and which gives to the several
portions of the civilized world the power of holding instantaneous
communication with each other, with a rapidity far beyond what has
ever before been attained. As the above explanation is given only in
reference to the power of the electro magnet, when connected with the
battery, and to show the movements of the pen lever, we shall speak of
the arrangement of the wires for extended lines hereafter.
Having now explained the electro magnet and its operation through the
agency of the battery, we will proceed to describe those various parts
of the register, by which the electro magnet is made subservient to the
transmission of intelligence from one distant point to another.
Figure 9 represents, in perspective, the whole of the register, as also
the key or correspondent. The electro magnet, H and H, and the pen
lever, L, which have just been described under figure 8, need not be
recapitulated here. The letters used in figure 8, represent the same
parts of the electro magnet in this figure.
The brass frame containing the clock work, or rather wheel work, of the
instrument, is seen at 5 and 5. The whole purpose of the clock work is
to draw the paper,[4] 2, 2, under the steel roller, S, and over the
pen, R, at an uniform rate.
[4] The paper used for telegraphic writing is first manufactured by
the paper making machine in one long continuous sheet, of any length,
about three feet and a half in width, and is compactly rolled up as it
is made, upon a wooden cylinder. It is then put into a lathe and marked
off in equal divisions of one and a half inches in width; a knife is
applied to one division at a time, and as the roll of paper revolves,
the knife cuts through the entire coil until it reaches the wooden
centre. This furnishes a coil ready for the register, and is about
fifteen inches in diameter. The whole roll of paper furnishes, in this
way, about twenty-eight small rolls prepared for use.
There is also an arrangement in connection with the wheel work, by
means of which the clock work is put in motion and stopped at the
pleasure of the operator at the distant station. How this is done will
now be explained. Upon the shaft, R′, is a brass barrel, upon which is
wound the cord to which the weight, 4, is suspended, and by means of
which and the intermediate wheels, the motion produced, is communicated
to two rollers (not seen in this figure, see fig. 10, E F) in advance
of the steel grooved roller, S. These two rollers grasp the paper, 2,
2, 3, between them, and supply it to the pen at a given and uniform
rate; the rate being determined by the adjustment of the wings of the
fly, connected with the train.
[Illustration: FIG. 9.]
[Illustration: FIG. 10.]
We will now describe, by figure 10, those parts connected with the
wheel work, which could not be easily shown in figure 9. F and E
represent, in outline, the two rollers which grasp the paper, 2 and 2.
The roller E is connected with the train by a cog wheel upon it. F is
not so connected; but is pressed hard upon E by means of springs upon
the ends of the axle; S represents the grooved steel roller beneath
which the paper, 2 and 2, is seen to pass. Directly under the steel
roller is one of the steel pen points at R, upon the end of the pen
lever; a part of which only is shown. Thus far the description given of
the clock work, relates to those parts, by the agency of which the pen
is supplied with paper. We now proceed to explain that part connected
with the clock and pen lever, by which the clock is set in motion or
stopped at the option of the distant operator.
In figure 9, at R′, is seen a small pulley upon the barrel shaft of the
clock work; at Q, is another pulley, but larger. From the pulley, R′,
is a cord,[5] or band, 10, proceeding to pulley, Q, and then returning
under it to pulley, R′, making it continuous. This band communicates
the motion of pulley, R′, to the pulley, Q. In figure 10, these pulleys
are represented by the same letters. B represents the barrel; the
arrow, the direction in which it revolves when in motion. The arrow at
Q shows the direction which it takes when motion is communicated to it
by R′. Part of the pulley, Q, is broken away in order to show the arm,
H, soldered at the middle of the same spindle upon which is the pulley,
Q, and directly beneath the pen lever, L. It is bent at D, so as to
turn down and strike the wooden friction wheel, C, at the point, P. The
friction wheel is secured upon the last spindle of the train at its
middle and directly under the lever, L. From the pen lever, L, is seen
a small rod of wire, A, passing down through the arm, H, with screw and
nut under it, at I, for the purpose of shortening or lengthening it. It
is permitted to work free, both at its connection with the lever and
arm. This wire is also extended and passes down through the platform,
where it operates upon a hammer for striking a bell, to apprise the
operator that a communication is to be sent. The several parts being
now explained, their combined action is as follows:
[5] The pulley and cord have been dispensed with and two small cog
wheels substituted.
The arm, H and D, is a break, which when brought in contact with the
friction wheel, C, prevents the weight of the clock work from acting
upon the train, and there is no motion. By the action of the magnet,
the pen lever, L, is carried up in the direction of the arrow, 3, and
takes with it the connecting rod, A, and also the break, H, D. The
break being thus removed from the friction wheel, C, the clock work
commences running by the power of the weight. The barrel, B, must
consequently turn in the direction of the arrow upon it; this motion
is communicated by the band to Q, which revolves in the direction of
its arrow; consequently, if the lever, L, is not still held up by the
magnet, the break is descending slowly; and when it reaches P, stops
the motion of the clock train, unless the pen lever continues in
motion, in which case the break, D, is kept up from the friction wheel,
thus permitting the clock work to run, until the lever ceases to move,
when the break is gradually brought down upon the friction wheel, and
the train stops. By this contrivance, the operator at a distance can so
control the movement of the paper at the remote register, that when he
wishes to write, it shall be put in motion, his pen be supplied with
paper, and when he has finished his writing, the register shall stop.
U represents (figure 9) the brass standards, one on each side of the
large roll of paper, 1, 1, 1, which it supports. Z is a wooden hub,
upon which the roll is placed; and 12, the steel arbor of the hub, and
upon which the whole easily revolves as the paper, 2 and 2, is drawn
off by the clock work. Y is a brass spring, between the hub and the
standard; and keeps the paper stretched between the roll and the pen.
[Illustration: FIG. 11.]
The key or correspondent is represented by 6, 7, 8, 9. Another view
of it is more distinctly seen in figure 11. The same letters in each,
represent the same thing. V and V is the platform. 8 is a metallic
anvil, with its smaller end appearing below, to which is soldered the
copper wire _c_. 7 is the metallic hammer, attached to a brass spring,
9, which is secured to a block, 6, and the whole to the platform, V V,
by screws. A copper wire passes through the whole, and is soldered to
the brass spring at 6. The key or correspondent is used for writing
upon the register at the distant station, and both it and the register
are usually upon the same table.
Having now explained the Register, Key and Battery, we proceed to
describe the arrangement of the conductors or wires connecting distant
stations, and the mode by which the earth, also, is made a conductor of
this subtle fluid.
The term _circuit_ used frequently in this work, has reference to the
wire, which, commencing at the positive pole of the battery, goes to
any distance and returns to the negative pole of the battery. When its
going and returning are continuous or unbroken, the circuit is said
to be _closed_ or _complete_. When it is interrupted, or the wire is
disconnected, the circuit is said to be _broken_ or _open_.
When a magnet or key or battery is spoken of as being _in the circuit_,
it has reference to the use of the wire belonging to the key, magnet or
battery, respectively, as a part of the circuit.
There are three modes of arranging the wires, so as to communicate
between two distant stations. Two of these modes are _inferior_, as
they furnish but one circuit for the termini, and consequently obliging
one station to wait, when the other is transmitting, both stations not
being able to telegraph at the same time. These two modes are called
the _dependent circuits_. The first mode is, where two wires are
used, of which figure 12 is a diagram. B represents Baltimore, and W
Washington; _m_ is the magnet or register; _k_ the key, and _bat_ the
battery, all at the Baltimore station; _m′_ is the magnet or register;
_k′_ the key at the Washington station. The lines, represent the wires
upon the poles, connecting the two stations, and are called the east
and west wires. In this arrangement of the wires and also in the
second, the key (which has been explained in a preceding figure, 11,
and shown at 6 and 7 to be open) must be closed at both stations, in
order to complete the circuit, except at the time when a communication
is being transmitted.[6] For the purpose of closing the circuit at the
key, a metallic wedge is used, which is put in between the anvil 8 and
the hammer 7, and establishes the circuit. Supposing the battery is in
action, and B has a communication for W: he opens his key, by removing
the wedge, and sends his message. The galvanic fluid leaves the point,
P, of the battery, and goes to _k_, to _m_, along the east wire to
_k′_, to _m′_, and back by the west wire to N pole of the battery. In
the same manner it proceeds along the wires, if W is writing to B. In
this arrangement, the direction of the galvanic current is the same,
whether B or W is communicating, unless the poles of the battery are
reversed.
[6] At this time the key is opened at the station from which the
communication is to be sent.
[Illustration: FIG. 12.]
[Illustration: FIG. 13.]
The second mode has but one wire and the ground, represented by figure
13. The use of the ground as a conductor of the galvanic fluid, between
two distant points, is to many a mystery. But of the fact there is no
question. The above diagram exhibits the manner in which the east wire
and ground were used from the first operation of the Telegraph, until
the close of the session of Congress, June, 1844. In this diagram, we
will minutely follow the course of the galvanic current. B represents
Baltimore, and W Washington; C represents a sheet of copper, five feet
long and two and a half feet wide, to which a wire is soldered and
connects with the N pole of the battery. This sheet of copper lies in
the water at the bottom of the dock, near the depot of the Baltimore
and Ohio Rail Road, Pratt street. From P of the battery, the wire
proceeds to _k_, the key, then to _m_, the magnet or register, then
it is the _east wire_ to _k′_, the key at W, then to _m′_, the magnet
or register, then to the _copper sheet_, C′, buried beneath the brick
pavement in the dry dust of the cellar of the capitol. The direction
of the current is from P of the battery to _k_, to _m_, and along the
east wire to _k′_, to _m′_, and to C′, where it is lost in the earth;
but reappears at the copper plate, C, at B, and thence to the N pole of
the battery, having completed its circuit. It is, therefore, certain,
that one-half of the circuit is through the earth. From B to W the east
wire is the conductor; and from W to B the ground is the conductor. In
this arrangement, the west wire is thrown out, and is no part of the
circuit; while the earth has been made a substitute for it.
[Illustration: FIG. 14.]
The last diagram, as has been stated, exhibits the plan of the
wire and ground, as used for telegraphic purposes, from its first
operation, until the adjournment of Congress in 1844, being prevented
from completing the arrangement of the third mode from the throng of
visitors, that pressed to see its operation. After the close of the
session, the following arrangement of the wires was made, as shown
in the diagram, figure 14, by means of which, both stations could
transmit at the same time, with one battery for both, and the keys
were not required to be closed. It is called the two _independent
circuits_. Here the west wire is used for transmitting from B to W;
and the east wire from W to B. The copper plates at B and W remain
as they are described in the second plan. _Bat_, the battery, at B
is used in common for both circuits. It is simply necessary here to
designate the course which the fluid takes when both lines are in
operation, viz. B transmitting to W; and W to B. In the former case,
the current is from P of the battery to _k_, then the _west wire_,
then to _m′_, at W, then to _C′_, thence through the ground to _C_ at
B, and then to the N, or negative pole of the battery, as shown by the
arrows. In the latter case, the current is from P of the battery to
_m_, then the _east wire_, then to _k′_, at W, thence to _C′_, thence
through the ground to C at B, thence to the N, or north pole of the
battery, as shown by the arrows. This arrangement, by which one battery
is made efficient for both circuits at the same time, where two were
formerly used, was devised by Mr. Vail, assistant superintendent, in
the spring of 1844, and has contributed much to diminish the care and
expense in maintaining that part of the apparatus of the telegraph. One
battery being now used instead of two. By the above diagram, it will
be perceived that the _ground_ is common to both circuits, as well as
the _battery_, and also the wire from the N pole of the battery, to
the copper plate, C; and from the copper plate, C′, to the junction
of the two wires near the two arrows. For the purposes of telegraphic
communication they answer as well as though there were four wires
and two batteries. Instead of using the ground between C and C′, a
wire might be substituted, extending from the N pole of the battery
to the junction of the wires at the two arrows at W. The arrangement
of the wires, battery, keys, magnets or registers at both stations,
with the ground, as shown in figure 14, is the plan now used for
telegraphic operations between B and W; and has many decided advantages
over the arrangements of figures 13 and 14. First. In both of those
arrangements, the circuit is obliged to be kept closed, when neither
station is at work; and as the battery is only in action when the
circuit is closed, it follows that the battery will not keep in action
as long as when the circuit is allowed to remain open, as in the use of
the third plan, figure 15. Second. There is an advantage in dispensing
with the use of the metallic wedge, which is liable to be forgotten by
the operator. Third. The attendant may occasionally leave the room, and
is not required to be in constant waiting, as the clock work is put in
motion and stopped by the operator at the other end, and the message
written without his presence. But in the first and second arrangement,
the apparatus for putting in motion and stopping the clock work, is
entirely useless. The attendant being obliged to put it in motion and
stop it himself.
We will now proceed to describe the modus operandi of transmitting
intelligence from one station to another; the arrangement being as
in figure 14; _k_ is the key of the operator at Baltimore, and _m′_
represents his register, or writing desk, at Washington; _k′_ is the
key of the operator at Washington, and _m_ his register, or writing
desk, at Baltimore. Each has the entire control of his respective
register, excepting, only, that each operator winds up the other’s
instrument, and keeps it supplied with paper. It will also be borne
in mind, that each circuit is complete, and everywhere continuous,
except at the keys, which are open. If, then, the hammer is brought in
sudden contact with the anvil, and permitted as quickly as possible to
break its contact by the action of the spring, and resume its former
position, the galvanic fluid, generated at the battery, flies its round
upon the circuit, no matter how quick that contact has been made and
broken. It has made the iron of the electro magnet a magnet; which
has attracted to it the armature of the pen lever; the pen lever, by
its steel pen points, has indented the paper, and the pen lever has,
also, by the connecting wire with the break; taken it from the friction
wheel; this has released the clock work, which, through the agency of
the weight, has commenced running, and the two rollers have supplied
the pen with paper. But, as only one touch of the key has been made,
the clock work soon stops again, if no other touches are made, by the
action of the break upon the friction wheel.
This shows the whole operation of the Telegraph, in making a single dot
by a single touch of the key. In order now to explain more fully the
operation of the steel pen points upon the paper, which is in contact
with the grooved roller, let there be made four touches at the key;
this will be sufficient to start the clock work, and allow the paper to
have attained a uniform rate; then let six touches be made at the key.
The contact has been made six times and broken six times. Each time it
is closed, the electro magnet, as heretofore explained, attracts to
it, with considerable force, the armature of the pen lever, carrying
up the steel pen points against the paper, 2, under the steel roller,
S. The three points of the pen, falling into the three corresponding
grooves of the roller, carry the paper with them and indent it,[7]
at each contact. There then appear upon the paper, as it passes out
from under the rollers, six indentations, as if it had been pressed
upon by a blunted point, such as the end of a knitting needle would be
supposed to make, when pressed upon paper, placed over a shallow hole,
but in such a manner as not to pass through the paper, but raising the
surface, as in the printing for the blind. These indentations of the
paper are the marking of the pen, but varied in the manner now to be
described.
[7] The first working model of the Telegraph was furnished with a
lead pencil, for writing its characters upon paper. This was found to
require too much attention, as it needed frequent sharpening, and in
other respects was found inferior to a pen of peculiar construction,
which was afterwards substituted. This pen was supplied with ink from
a reservoir attached to it. It answered well, so long as care was
taken to keep up a proper supply of ink, which, from the character of
the letters, and sometimes the rapid, and at others the slow rate of
writing, was found to be difficult and troublesome. And then again,
if the pen ceased writing for a little time, the ink evaporated and
left a sediment in the pen, requiring it to be cleaned, before it was
again in writing order. These difficulties turned the attention of the
inventor to other modes of writing, differing from the two previous
modes. A variety of experiments were made, and among them, one upon
the principle of the manifold letter writers; and which answered
the purpose very well, for a short time. This plan was also found
objectionable, and after much time and expense expended upon it, it was
thrown aside for the present mode of marking the telegraphic letter.
This mode has been found to answer in every respect all that could be
desired. It produces an impression upon the paper, not to be mistaken.
It is clean, and the points making the impression being of the very
hardest steel, do not wear, and renders the writing apparatus always
ready for use.
By examining the telegraphic alphabet, the characters will be found to
be made up of dots: short and long lines—and short and long spaces.
A single touch of the key, answers to a single dot on the paper of
the register; which represents the letter, E. One touch of the key
prolonged, that is, the contact at the key continued for about the
time required to make two dots, produces a short line, and represents
T. A single touch for about the time required to make four dots, is
a long line, and represents L. A single touch for about the time
required to make six dots, is a still longer line and represents the
0 of the numerals. If the use of the key be suspended for about the
time required to make three dots, it is a short space, used between
letters. If suspended for the time required to make six dots, it is a
long space, used between words, and a longer space is that used between
sentences. These are the elements which enter into the construction of
the telegraphic characters, as used in transmitting intelligence. The
alphabet is represented by the following combination of these elements.