In the following table, the first column represents the keys, which
when depressed, produce a deflection of the needles, (represented in
the columns, second, third and fourth,) by means of their batteries,
and thus closing the circuit of the wires, ̈1, ̈2, ̈3, ̈4, ̈5 and ̈6,
by which the fluid, is made to pass through the prepared fabric, and
mark upon its space, or spaces, numbered 1, 2, 3, 4, 5 and 6, in the
fifth column. In the sixth column are the letters which the marks upon
the fabric are intended to represent.
Keys. Needles. Needles. Needles. Spaces on Fabric. Letters.
H, 7, A, T, - - 1, A.
J, 7, A, S, - - 2, B.
K, 7, B, T, - - 3, C.
M, 7, B, S, - - 4, D.
O, 7, C, T, - - 5, E.
U, 7, C, S, - - 6, F.
H, K, 7, A, T, B, T, - 1, 3, G.
J, M, 7, A, S, B, S, - 2, 4, H.
K, O, 7, B, T, C, T, - 3, 5, I.
M, U, 7, B, S, C, S, - 4, 6, J.
H, O, 7, A, T, C, T, - 1, 5, K.
J, U, 7, A, S, C, S, - 2, 6, L.
H, M, A, T, B, S, - 1, 4, M.
J, K, A, S, B, T, - 2, 3, N.
K, U, B, T, C, S, - 3, 6, O.
M, O, B, S, C, T, - 4, 5, P.
H, U, A, T, C, S, - 1, 6, Q.
J, O, A, S, C, T, - 2, 5, R.
H, K, O, 7, A, T, B, T, C, T, 1, 3, 5, S.
J, M, U, 7, A, S, B, S, C, S, 2, 4, 6, T.
H, K, U, A, T, B, T, C, S, 1, 3, 6, U.
J, M, O, A, S, B, S, C, T, 2, 4, 5, V.
H, M, U, A, T, B, S, C, S, 1, 4, 6, W.
J, K, U, A, S, B, T, C, S, 2, 3, 6, X.
H, M, O, A, T, B, S, C, T, 1, 4, 5, Y.
J, K, O, A, S, B, T, C, T, 2, 3, 5, Z.
_Telegraphic Letters._
1 · · · · · · · · ·
2 · · · · · · · · ·
3 · · · · · · · · ·
4 · · · · · · · · ·
5 · · · · · · · · ·
6 · · · · · · · · ·
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
The above represents the telegraphic characters marked upon the
prepared fabric. The spaces are numbered from the top.
The first six of the telegraphic letters require each a signal wire,
and the common wire, D, with one battery.
The next six require each two signal wires, with two batteries, whose
joint currents pass in the same direction on the common wire, D.
The next six require each two signal wires only, with two batteries,
joined together so as to form a compound battery. The negative pole of
one, connected with the positive pole of the other.
The next two require each three signal wires, with three batteries,
whose joint currents pass in the same direction along the common wire,
D.
The next six require each, three _signal_ wires only, with three
batteries. One of the signal wires with its battery is used as a common
wire for the other two. Hence the current of the two batteries of the
two signal wires unite in one, and are connected with the battery of
the common wire as a compound battery.
With what rapidity these letters may be formed, does not appear, or to
what extent the plan has been carried out.
_Bain’s Printing Telegraph._
The following description of Mr. Bain’s plan of what he calls an
_electro magnetic_ printing telegraph, is taken from a work entitled,
“An account of some remarkable applications of the electric fluid to
the useful arts, by Alexander Bain. Edited by John Finlaison, Esq.
London, 1843.”
It appears from this work that Mr. Bain’s plan was invented in 1840,
and the following certificate is given in reference to the date of its
first operation.
PERCEIVAL STREET, CLERKENWELL, _Aug. 28, 1842_.
DEAR SIR—In reference to your application,
I recollect visiting you at your apartments in Wigmore
street, early in July, 1840, when you showed me the model
of your _electro magnetic_ printing telegraph, with which
you printed my name at the time. You also showed me a model
of your electro magnetic clock, and explained to me the
principles and utility of them.
I remain, dear sir, yours, respectfully,
ROBERT C. PINKERTON.
To MR. ALEXANDER BAIN.
[Illustration: FIG. 76. PORTSMOUTH.]
[Illustration: FIG. 77. LONDON.]
Figures 76 and 77 exhibit the arrangements of Mr. Bain’s telegraph.
Both figures are the same, representing one as being at _Portsmouth_,
and the other at _London_. The same letters will refer to either
instrument: _d_, _i_ and _h_, represent the signal dials, insulated
from the machine. X is a hand or pointer. The small dots represent
twelve holes in the dial, corresponding with the twelve signals, and
two blanks, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0. U is a similar hole over the
starting point of the hand, X. R is a coil of wire, freely suspended
on centres. K and K, is a compound permanent magnet, placed within the
coil, and immovably fixed upon the frame of the machine. J and J are
sections of similar permanent magnets. S is a spiral spring, (and there
is another on the opposite side,) which conveys the electric current
to the wire coil, and at the same time leaves the coil free to move
in obedience to the magnetic influence. So long as the electricity
is passing, the wire coil continues to be deflected, but the instant
the electric current is broken, the springs, S, bring back the coil
to its _natural position_.[36] L is an arm fixed to, and carried by
the wire coil, R and R, to stop the rotation of the machinery. B is a
main spring barrel, acting on the train of wheels, G, H and I, which
communicate motion to the governor, W, and the hand, X. On the arbor
of the wheel, H, is fixed a type wheel, C, at a little distance from
the paper cylinder, A, on which the messages are to be imprinted. P
is a second main spring barrel, with its train of wheels, M, O. Q, is
a fly, or vane. On the arbor of the wheel, _o_, there is a crank, V,
and two pallets, _a_ and _b_, which prevent the train of wheels from
rotating, by coming in contact with the lever, Z. When the telegraph is
not at work, a current of electricity is constantly passing from the
_Portsmouth plate_, buried in the ground, through the moisture of the
earth, to the plate in the ground at the _London_ station. From the
copper plate of that station the electric current passes up through
the freely suspended multiplying coil, R and R, (which it deflects to
the horizontal position,) into the machinery, and thence to the dial,
by means of a metal pin, inserted in the hole, U; from the dial it
passes by a single insulated conducting wire, 1, suspended in the air,
back to the first machine; traversing which, it passes through the
freely suspended multiplied coil, R and R, which it deflects, also, to
the horizontal position to the plate from whence it started, and thus
completes the circuit.
[36] Mr. Bain means, by the _deflected position_ of the coil, (when the
current is passing,) its _horizontal_ position, as shown in the figure.
Its _natural_ position, (when the current is broken,) is the elevation
of the left hand end of the coil, in the direction of the arrow,
carried up by the power of the spring, at the centre of the coil.
This action of the spring is overcome, when the current is passing,
to such a degree, as to bring the coil to the horizontal position as
represented in the figure.
“When a communication is to be transmitted from either end of the line
(one station only being able to transmit at a time,) the operator draws
out the metal pin from the hole, U, in the dial of his machine; the
electric circuit is then broken, and the ends of the multiplying coils,
R and R, at both stations are carried upwards, in the direction of the
arrow, by the force of the spiral springs. The arms, L, attached to
the two coils, moving to the right, release the lever, Y, which leaves
the machinery free to rotate, and as the moving and regulating powers
are the same at both places,[37] the machines go accurately together;
that is, the hands of both machines pass over similar signals at the
same _instant_ of time, and similar types are continually brought
opposite to the printing cylinders at the same moment. An inspection
of the wheel work will show, that this movement will have caused the
governor, W, to make several revolutions, and the divergence of the
balls, in obedience to centrifugal force, will have raised one end of
the lever, Z, and depressed the other, which allows the pallet, _a_,
to escape; but the rotation of the arbor is still opposed by contact
with the second pallet, _b_. The operator having inserted the metal
pin in the hole, under the signal which he wishes to communicate, the
moment the hand of the dial comes in contact with it, the circuit is
again completed, and both machines are stopped instantly. The governor
balls, collapsing, depress the left hand end of the lever, Z, clear
the pallet, _b_, and this allows the crank spindle, V, to make one
revolution.
[37] It is absolutely necessary to the certain and accurate performance
of the two machines, that their movements should be synchronical, or
else a different figure, or signal, from that intended by the operator
at the transmitting station, may be given at the receiving station.
“The motion of the crank by means of the crank rod, T, acting on the
lever, E, presses the type against the paper cylinder, A, and leaves an
impress upon the paper; at the same time, a spring, _e_, attached to
an arm of the lever, E, takes into a tooth of the small ratchet wheel,
D, on the spindle of the long pinion, F, which takes into and drives
the cylinder wheel; so that the crank apparatus, going back to its
former position, after impressing a letter, moves the signal cylinder
forward, and presents a fresh surface to the action of the next type.
As the cylinder moves round, it has also a spiral motion upward, which
causes the message to be printed in a continuous spiral line until the
cylinder is filled.[38] In order to mark, in a distinct and legible
manner, the letters printed by the apparatus, two thicknesses of
riband, saturated with printing ink and dyed, are supported by two
rollers so as to interpose between the type wheel and the cylinder;
(the rollers are not shown in the figure, to prevent confusion.) If a
second copy of the message, thus simultaneously printed at two distant
places, is desired at either, a slip of white paper is placed between
the ribands to receive the imprint at the same time as the cylinder.”
[38] This contrivance for moving the paper is exactly similar to that
in Prof. Morse’s _first model_ of his telegraph, made in 1837, for the
Patent Office.
[Illustration: FIG. 78.]
Figure 78 represents a top view of the coil and magnets of Mr. Bain’s
machine. B is the compound permanent magnet, with six bars. N is the
north pole, and S the south pole. A, A are the sides of the brass frame
containing the coils; C, C are the spiral springs on each side: _a_ and
_a_ is the axis of the coil: _o, o_, is a part of the frame containing
the clock work, (not shown in this figure,) supporting one centre of
the coil, and I and I a support for the other centre. N and P are the
wires, one of which is in connection with the ground, and the other
with the extended wire. When the circuit is closed, and the current
from P pole of the battery is in the direction of the arrow above, and
then through the coil to the other pole, N, in the direction of the
arrow below; the end, D, of the coil, will be depressed, and the end,
U, will rise; reverse the current and the effect is the elevation of
the end, D, of the coil, and the depression of the end, U.
_Wheatstone’s Rotating Disc Telegraph, invented, 1841._
Figure 79 represents that portion of the instrument which belongs to
the _transmitting_ station, of which, K, is a circular disc, with the
alphabet and numerals, marked in two concentric circles upon it: _a_
are handles projecting from its rim, one to every letter, by means of
which, the disc is turned upon its axis, and brought to that position,
_b_, required for signalizing a letter. O is a side view of the disc,
K: _t_ is the rim of the disc, with its holders: _h_ is a portion of
the axis of the disc, shown as broken off: _c_ represents a silver
band surrounding a pulley, or hub, upon the axis, and directly behind
the disc. Upon the hub are metallic ribs, _b_, parallel with its axis,
corresponding in number to the letters on the dial. Each rib forms a
metallic contact with the silver band, _c_, and are separated from each
other by pieces of ivory, fastened to the hub. Both the ribs and ivory
pieces are made perfectly smooth and even upon their surface: _e_ is
a metallic spring with a portion of it pressing against that portion
of the hub between the silver band, _c_, and the disc, _t_, in such a
manner that when the disc is turned, the metallic ribs and ivory pieces
shall alternately come in contact with it. To this spring is soldered
a wire connected with one pole of the battery, _g_, and from the other
pole proceeds the wire, _n_: _d_ is another metallic spring, similar to
_e_, but pressing _only_ upon the silver band, with which it is always
in contact, and to which a wire, _p_, is soldered. Whenever the spring,
_e_, is in contact with any of the metallic ribs, there is a continuous
connection from _n_ to _p_, viz. from _p_, to the spring in contact
with the silver band, _c_, thence to the rib with which the spring,
_e_, is in contact; then to the spring, _e_, then to the battery, _g_,
and then to the wire, _n_. If, however, the disc, O, should be turned,
so that the spring, _e_, is in contact with the ivory, then the circuit
is broken at that point, and in this manner the circuit is alternately
broken and closed as the wheel, O, is turned from one letter to another
by means of the handles at _t_.
[Illustration: FIG. 79.]
[Illustration: FIG. 80.]
Figure 80 represents a side elevation of the dial and clock work of the
_receiving station_. A represents an edge view of the electro magnet,
from which proceed the two wires, _v_ and _i_, which connect with the
wires, _n_ and _p_, of figure 79. J and J is the brass frame containing
the wheel work, C and E; the pin wheel, D; the dial plate, I; and the
barrel, B, which is driven by a weight and cord. In the side of the
wheel, D, are pins projecting from the rim, parallel with the axis, and
are equal in number to the divisions, or letters, upon the dial, I.
They are, however, placed alternately on each side of the rim. F is the
armature of the magnet, fastened upon a horizontal rod, sliding freely
through the standards, 1 and 2. G represents a spring, fastened to the
frame, J, and which carries back the armature, F, when the magnet has
ceased to attract it. From the armature there extends downward an arm,
K, which, as it approaches the pin wheel, D, presents two arms, or
pallets, one on each side of the wheel. These pallets are so arranged
with regard to the pins, that if one pallet releases a pin on one side
of the wheel, the same movement will cause the other pallet on the
other side, to arrest the motion of the wheel by its striking against
the next alternate pin. H and I is an edge view of the circular dial,
enclosed in a case, with a single opening at O, so that only one letter
at a time can be seen. This dial, I, is in every respect marked as the
disc in figure 79.
Figure 81 represents the two instruments. O the _transmitting_
instrument, and the right hand figure the _receiving_ instrument. The
wires, _v_ and _i_, are respectively connected with _p_ and _n_. It
will be observed, that the armature, F, is not attracted, and that
the right hand pallet is checking the pin wheel, so that the dial is
stationary. If, however, the disc, _t_, is turned so that the circuit
is completed, by the contact of the spring, _e_, with one of the ribs,
instantly the armature is attracted by the electro magnet, which will
carry the right hand pallet away from the pin wheel, and which will
then move by the action of the weight upon the barrel, B, until it is
checked by the left hand pallet, which had advanced to the wheel at
the same time the other receded. This single operation has moved the
disc one division and the armature is still attracted. Now let the
disc, _o_, be turned until the spring, _e_, has been passed by the rib,
and is in contact with the ivory only, instantly the current ceases;
the armature, F, recedes from the magnet by the action of the spring,
G; this has taken the left hand pallet from the pin wheel, which is
permitted to move until the next pin strikes against the right hand
pallet. This has now brought another letter in front of the aperture at
H. Thus it will be seen, that the design of this instrument is to bring
into view, at the aperture such letters as are required in transmitting
a message.
[Illustration: FIG. 81.]
Suppose letter A, is at the point, _b_, of the _disc_; and letter A
of the _dial_ is opposite the opening; the instrument is now ready
to transmit, and let the letter, I, be the first of the message. The
operator gently turns the disc round in the direction of the arrow,
so that each time the circuit is broken a new letter appears at the
dial, and each time it is closed by the operation of the pallets, in
checking and releasing the pin wheel. This is its operation until the
letter, I, has reached the point, _b_, when a short pause is made. The
next letter, H, requires but one movement of the disc, then follows, A;
then, V; and then, E.
In relation to this instrument, Professor Daniell says: “We can only
further briefly allude to two of the most important modifications of
this invention, which Prof. Wheatstone has made for specific purposes.
By substituting for the paper disc, on the circumference of which the
letters are printed, a thin disc of brass, cut from the circumference
to the centre, so as to form 24 springs, on the extremities of which,
types, or punches, are placed, and adding a mechanism the detent of
which, acted on by an electro magnet, causes a hammer to strike the
punch against a cylinder, round which are rolled, alternately, several
sheets of white paper, and of the blackened paper used in the manifold
writing apparatus, he has been enabled to obtain, without presenting
any resistance to the type wheel, several distinct printed copies at
the same time of the message transmitted.”[39]
[39] Daniell’s Introduction to Chemical Philosophy, page 580, 2d
Edition, London, 1843
Mr. Wheatstone has recently so modified his telegraph as to use two
needles, or galvanometers, and two extended wires, with the ground as
half the circuit for the two wires. He has thus adopted PROF. MORSE’S
_plan_ of using the ground as a common conductor for two or more wires.
He, however, still requires two wires for _one_ independent line of
communication; one station only being able to communicate at a same
time. He has no mode of recording his message, but depends upon the
watchful eye of the attendant. His code of signals are based upon
Schilling’s plan, heretofore described, page 155, and also Gauss and
Weber’s, page 156, from whom he seems to have obtained his idea.
The two needles, or galvanometers, stand side by side, one of which is
called the _left_ needle and the other the _right_ needle. These two
needles are placed directly in front of the person who transmits. There
are, also, in front, two handles, one for each hand, with which the
operator transmits a message, closing and breaking the circuit of the
two wires. His signals are made thus: The upper half of the left hand
needle moving to the left twice, gives, _a_; three times, _b_; once to
the right and once to the left, _c_; once to the left and once to the
right, _d_; and, in like manner, for the other letters of the alphabet,
as shown in the table which follows.
Left Hand Needle. Right Hand Needle.
ll, A. r, E. | l, H. lr, M.
lll, B. rr, F. | ll, I. r, N.
rl, C. rrr, G. | lll, K. rr, O.
lr, D. | rl, L. rrr, P.
Joint Action of Both Needles.
l, l, R.
ll, ll, S.
lll, lll, T.
rl, rl, U.
r, r, W.
rr, rr, X.
rrr, rrr, Y.
r, completed.
ll, rr, I understand, or yes.
rl, rl, I do not understand, or no.
rl, rl, 1.
lr, lr, 2.
r, r, 3.
l, l, 4.
rl, rl, 5.
lr, lr, 6.
r, r, 7.
l, l, l, l, 8.
ll, ll, ll, ll, 9.
r, r, r, r, 0.
Mr. Wheatstone does not appear to be aware of all the advantages of
this, his latest plan of using two needles and two wires, since some
of his signals for the _numerals_, are repetitions of his _letter_
signals, and require four deflections of a single needle, with a pause
between the two first deflections, and the two last, and for _some_
other signals he requires as many as three deflections of a signal
needle. He has likewise, apparently, for want of simple signals,
omitted the letters, J, Q, V, Z. He could with perfect ease, obtain
from his two wires and two needles, sixty-four different signals,
requiring the time of only two deflections, each, and using but one
hand for manipulating four keys, instead of both hands, as in his
present plan. The author has demonstrated it by actual experiment.