We presume it will not be uninteresting to the reader, to be presented
with an account of the various discoveries, in their chronological
order, by which the science of Electricity became known to the world
during the seventeenth and eighteenth centuries, and prepared the
way for those more magnificent results, which have been made in this
the nineteenth century. We will endeavour to make it as brief as is
consistent with the importance of the subject, to enable us to mark the
succession of discoveries and improvements through two hundred years.
More than any other branch of experimental philosophy, that of
electricity had been most neglected, until the seventeenth century. The
attractive power of amber is mentioned by Theophrastus and Pliny, and
also later by others.
[16]
In the year 1600, William Gilbert, a native of Colchester, and a
London physician, published a Latin Treatise, De Magnete, in which
he relates a variety of electrical experiments. He increased the list
of electric bodies and also of substances upon which electrics could
act, and noted some of the circumstances relating to their action. His
theory of electricity was, however, very imperfect.
In 1630, Nicolaus Cabœus at Terrara, repeated Gilbert’s experiments
and made some progress, increasing the list of electrics; as also did
Mr. Boyle in the year 1670. He made some discoveries which had escaped
the observation of those who preceded him. Cotemporary with Mr. Boyle,
Otto Guericke, burgomaster of Magdeburg, (the inventor of the air
pump,) made some advances. He constructed a sulphur globe, which he
mounted upon an axis, in a wooden frame, and causing it to revolve, at
the same time rubbing the globe with his hand, performed a variety of
electrical experiments. He was the first to discover, that a body once
attracted by an excited electric, was repelled by it, and not again
attracted until it had touched some other body. He observed the light
and sound produced by the electric fluid, while turning his electrical
machine. Dr. Wall about the same time observed the light and sound
produced by rubbing pieces of amber with wool, and also experienced a
slight shock. He compared the sound and light of the electric fluid so
produced, to thunder and lightning.
Sir Isaac Newton also engaged in similar electrical experiments, and
gave an account of them to the Royal Society in 1675. Mr. Hauksbee,
whose writings are dated 1709, distinguished himself by experiments
and discoveries in electrical attraction, and repulsion, and electric
light. He constructed an electrical machine, adopting the glass,
instead of the sulphur globe. He experimented upon the subtilty and
copiousness of the electric light, and likewise upon the sound and
shocks produced by the fluid. After the death of Mr. Hauksbee, the
science of electricity made but slow progress, and few experiments
were made for twenty years. In the year 1728, Mr. Stephen Grey, a
pensioner at the Charter House, commenced his experiments with an
excited glass tube. He and his friend, Mr. Wheeler, made a great
variety of experiments in which they demonstrated, that electricity
may be communicated from one body to another, even without being in
contact, and in this way, may be conducted to a great distance. Mr.
Grey afterwards found, that, by suspending rods of iron by silk or hair
lines, and bringing an excited tube under them, sparks might be drawn,
and a light perceived at the extremities in the dark. He electrified
a boy suspended by hair lines; and communicated electricity to a soap
bubble blown from a tobacco pipe. He electrified water, contained in a
dish, placed upon a cake of rosin, and also a tube of water. He made
some curious experiments upon a small cup of water, over which, at the
distance of an inch, he held the excited tube. He observed the water to
rise in a conical shape, from which proceeded a light; small particles
of water were thrown off from the cone, and the tube moistened.
Mr. Du Fay, intendant of the French king’s gardens, repeated the
experiments of Mr. Grey in 1733. He found that by wetting the
pack-thread he succeeded better with the experiment of communicating
the electric virtue through a line 1256 feet in length. He made the
discovery of two kinds of electricity, which he called vitreous and
resinous; the former produced by rubbing glass, and the latter from
excited sulphur, sealing wax, &c. But this he afterwards gave up as
erroneous. Mr. Grey, in 1734, experimented upon iron rods and gave
rise to the term metallic conductors. He gave the name pencil of
electric light to the stream of electricity, such as is seen to issue
from an electric point. He suggested the idea that the electric virtue
of the excited tube was similar to that of thunder and lightning, and
that it could be accumulated.
Dr. Desaguliers commenced his experiments in 1739. He introduced the
term conductor to that body to which the excited tube conveys its
electricity. He called bodies in which electricity may be excited
by rubbing or heating, electric per se; and non-electric when
they receive electricity, and lose it at once upon the approach of
another non-electric. In the year 1742, several Germans engaged in
this subject. Mr. Boze, a professor at Wittemburg, revives the use of
Hauksbee’s globe, instead of using Grey’s glass tube, and added to it
a prime conductor. Mr. Winckler substituted a cushion instead of
the hand, which had before been employed to excite the globe. Mr. P.
Gordon, a Benedictine monk and professor of philosophy at Erford, was
the first who used a cylinder instead of a globe. With his electrical
machine he conveyed the fluid through wires 200 ells in length and
killed small birds. Dr. Ludolf of Berlin, in the year 1744, kindled by
electricity the ethereal spirit of Frobenius, by the excited glass
tube; the spark proceeding from an iron conductor. Mr. Boze fired
gunpowder by electricity. Mr. Gordon contrived the electrical star. Mr.
Winckler contrived a wheel to move by the agency of the same fluid.
Mr. Boze conveyed electricity from one man to another by a jet of
water, when both were placed upon cakes of rosin, six paces apart. Mr.
Gordon fired spirits, by a jet of water; and the Germans invented the
electrical bells.
Mr. Collinson in 1745 sent to the Library Company of Philadelphia, an
account of these experiments, together with a tube, and directions how
to use it. Franklin, with some of his friends, immediately engaged
in a course of experiments, the results of which are well known. He
was enabled to make a number of important discoveries, and to propose
theories to account for various phenomena, which have been universally
adopted, and which bid fair to endure for ages.
In the year 1745, such was the attention given to the subject of
electricity, that experiments upon it were publicly advertised and
exhibited for money in Germany and Holland. Dr. Miles, of England, in
the same year fired phosphorus by the application of the excited tube
itself without the intervention of a conductor. It was at this period
that Dr. Watson’s attention was given to this subject. He fired air,
made inflammable by a chemical process, and discharged a musket by
the electric fluid. He made many experiments, some of which will be
described as we proceed.
The year 1745 was made famous by the discovery of the Leyden Phial by
Mr. Cuneus a native of Leyden. It appears also to have been discovered
by Mr. Von Kleist, dean of the Cathedral in Camin about the same time.
By this discovery, electricity could be accumulated and severe shocks
given. Mr. Gralath, in 1746, gave a shock to twenty persons at once,
and at a considerable distance from the machine. He constructed the
electrical battery by charging several phials at once. Mr. Winckler,
and also M. Monnier, in France, transmitted the electric fluid through
several feet of water as a part of the circuit. M. Nollet, in
France, killed birds and fishes by the discharge of the Leyden jars.
Improvements were made by Dr. Watson, and others, in the Leyden phial,
by coating the inside and outside of it with tin foil. Abbé Nollet
gave a shock to 180 of the guards in the king’s presence; and at the
grand convent of the Carthusians in Paris, the whole community formed a
line of 3600 feet in length, by means of wires between them. The whole
company upon the discharge of the phial, gave a sudden spring at the
same instant. The French philosophers tried the same experiment through
a circuit of persons, holding wires between them, two and a half
miles in length. In another experiment the water of the basin in the
Tuilleries was made a part of the circuit.
M. Monnier, the younger, to discover the velocity of electricity,
discharged the Leyden phial through an iron wire 4000 feet in length,
and another 1319 feet, but could not discover the time required for
its passage. Dr. Franklin communicated his observations, in a series
of letters, to his friend Collinson, the first of which is dated March
28, 1747. In these he shows the power of points in drawing and throwing
off the electrical matter. He also made the grand discovery of a plus
and minus, or of a positive and negative state of electricity.
Shortly after Franklin, from his principles of plus and minus state,
explained, in a satisfactory manner, the phenomena of the Leyden phial.
Dr. Watson and others in July 18, 1747, conveyed the electric fluid
across the Thames at Westminster bridge; the width of the river making
a part of the circuit. On the 24th of July, he tried the experiment
of forcing the electric fluid to make a circuit with the bend of the
river, at the New River at Stoke, Newington. He supposed that the
electric fluid would follow the river alone, through its circuitous
windings, and return by the wire. He suspected from the result of this
experiment, that the ground also conducted the fluid. On the 28th, he
proved the fact by supporting a wire 150 feet in length upon baked
sticks, using the ground as half of the circuit. On the 5th, of August,
he tried another experiment of making the dry ground a part of the
circuit for a mile in extent, and found it to conduct equally as well
as water. The last experiment was tried at Shooter’s Hill, on the 14th
of August of the same year. But one shower of rain had fallen for the
five preceding weeks. The wires, two miles in length, were supported
upon baked sticks, and the dry ground was used for the return two miles
of the circuit. They found the transmission of the electric fluid to
be instantaneous. Dr. Watson made many other experiments which we must
pass over.
Mr. Ellicott constructed an electrometer for measuring the quantity of
electricity. Mr. Maimbury, at Edinburgh, electrified two myrtle trees,
during the month of October, 1746, when they put forth small branches
and blossoms sooner than other shrubs of the same kind, which had not
been electrified. The same experiment was tried upon seeds, sowed in
garden pots with the same success. Mr. Jallabert, Mr. Boze and the Abbé
Menon principal of the College of Bueil, at Angers, tried the same
experiments upon plants, by electrifying bottles in which they were
growing. He proved that electrified plants always grew faster, and had
finer stems, leaves and flowers than those which were not electrified.
In the year 1748, Dr. Franklin, and his friends, held an
electrical feast[17]
on the banks of the Schuylkill near Philadelphia, and as the account
is amusing, as well as scientific, we will give an account of it
as related by Franklin, in a letter to his friend Collinson, dated
Philadelphia, 1748. (1 vol. of Franklin’s Works, p. 202.)
“Chagrined a little that we have been hitherto able to produce nothing
in this way of use to mankind; and the hot weather coming on, when
electrical experiments are not so agreeable, it is proposed to put
an end to them for this season, somewhat humorously, in a party of
pleasure, on the banks of the Skuykil.”
“Spirits, at the same time, are to be fired by a spark sent from
side to side through the river, without any other conductor than
the water, an experiment which we some time since performed, to the
amazement of many. A turkey is to be killed for our dinner by the
electrical shock, and roasted by the electrical jack, before a
fire kindled by the electrified bottle: when the healths of all the
famous electricians of England, Holland, France, and Germany are to be
drank in electrified bumpers,[18]
under a discharge of guns from the electrical battery.”
“In the year 1749, Franklin first
suggested his idea of explaining the phenomena of thunder gusts, and
of the aurora borealis, upon electrical principles. He points out
many particulars in which lightning and electricity agree; in the
same year he conceived the bold idea of ascertaining the
truth of his doctrine, by actually drawing down the lightning, by means
of sharp pointed iron rods, raised into the region of the clouds.
Admitting the identity of electricity and lightning, and knowing the
power of points in repelling bodies charged with electricity, and in
conducting the fluid silently and imperceptibly, he suggested the idea
of securing houses, ships, &c. from being damaged by lightning, by
raising pointed rods several feet above the most elevated part of the
building to be protected, and the other end descending some feet into
the ground. It was not until the summer of 1752, that he was enabled to
complete his grand discovery by experiments.”
“While he was waiting for the erection of a spire, it occurred to
him that he might have more ready access to the region of clouds, by
means of a common kite. He prepared one by fastening two cross sticks
to a silk handkerchief, which would not suffer so much from the rain
as paper. To the upright stick was affixed an iron point. The string
was, as usual, of hemp, except the lower end, which was silk. Where
the hempen string terminated, a key was fastened. With this apparatus,
on the appearance of a thunder gust approaching, he went out into the
commons, accompanied by his son, to whom alone he communicated his
intentions, well knowing the ridicule which, too generally for the
interests of science, awaits unsuccessful experiments in philosophy. He
placed himself under a shade, to avoid the rain; his kite was raised—a
thunder cloud passed over it—no sign of electricity appeared. He
almost despaired of success, when, suddenly, he observed the loose
fibres of his string to move towards an erect position. He now
presented his knuckle to the key, and received a strong spark; repeated
sparks were drawn from the key; a phial was charged, a shock given, and
all the experiments made which are usually performed with electricity.”
“Franklin constructed rods so as to bring the lightning into his house,
for the purpose of ascertaining if it was of the positive or negative
kind. He succeeded in the experiment for the first time in April, 1753,
when it appeared that the electricity was negative. On the 6th of June
he met with a cloud electrified positively. The discoveries of Franklin
roused the attention of all Europe, and many distinguished electricians
repeated them with success. Professor Richman, of St. Petersburg, while
making some experiments upon the electrical state of the atmosphere,
was killed by the electric fluid, August, 1753. Towards the end of the
eighteenth century, electricity was assiduously cultivated by a great
number of eminent individuals, who extended the boundaries of the
science by numerous experiments, and by the invention of ingenious and
useful instruments. Experiments were made upon air, water and ice; and
in relation to the surfaces of electric bodies; in relation to the two
electrical states; upon the deflagration of the metals; decomposition
of solids and liquids,” &c. &c.
It is stated in Young’s Travels in France, (1787, 4th ed. vol. 1, p.
79,) that a Mr. Lomond had invented a mode by which, from his own room,
he held communication with a person in a neighbouring chamber, by means
of electricity. He employed the common electrical machine placed at one
station, and at the other an electrometer constructed with pith balls.
These instruments were connected by means of two wires stretched from
one apartment to the other; so that, at each discharge of the Leyden
phial, the pith balls would recede from each other, until they came in
contact with the return wire. His system of telegraphic correspondence
is not related. We must suppose from the character of his invention,
having but one movement, that of the divergence of the balls, and using
an apparatus extremely delicate, that his means of communication could
not have been otherwise than limited, and required a great amount of time.
The only mode in which it appears possible for him to have transmitted
intelligence, seems to be this: a single divergence of the pith balls,
succeeded by an interval of two or three seconds, may have represented
A. Two divergencies in quick succession, with an interval following,
may have represented B; three divergencies, in like manner, indicated
the letter C; and so on for the remainder of the alphabet. Instead of
these movements of the pith balls representing letters, they may have
indicated the numerals 1, 2, 3, &c. so that with a vocabulary of words,
numbered, conducted his correspondence. This appears to be the first
electrical telegraph of which we have any account; but does not appear
to have been used upon extended lines.
In 1794, according to Voigt’s Magazine, vol. 9, p. 1, Reizen made use
of the electric spark for telegraphic purposes. His plan was based upon
the phenomenon which is observed when the electric fluid of a common
machine is interrupted in its circuit by breaks in the wire, exhibiting
at the interrupted portions of the circuit a bright spark. The spark thus
rendered visible in its passage he appears to have employed in this manner.
Fig. 34.
Figure 34 is a representation of the table upon which
were arranged the letters of the alphabet, twenty-six in number. Each letter is
represented by strips of tin foil, passing from left to right, and
right to left, alternately, over a space of an inch square upon a
glass table. Such parts of the tin foil are cut out, as will represent
a particular letter. Thus, it will be seen that the letter A is
represented by those portions of the tin foil which have been taken
out, and the remaining portions answer as the conductor. P and N
represent the positive and negative ends of the strips, as they pass
through the table and reappear, one on each side of the small dot
at A. Those two lines which have a dot between, are the ends of the
negative and positive wire belonging to one of the letters. Now if a
spark from a charged receiver is sent through the wires belonging to
letter A, that letter will present a bright and luminous appearance
of the form of the letter A. “As the passage of the electric fluid
through a perfect conductor is unattended with light, and as the light
or spark appears only where imperfect conductors are thrown in its
way, hence the appearance of the light at those interrupted points of
the tin foil; the glass upon which the conductors are pasted, being
an imperfect conductor. The instant the discharge is made through the
wire, the spark is seen simultaneously at each of the interruptions, or
breaks, of the tin foil, constituting the letter, and the whole letter
is rendered visible at once.” This table is placed at one station, and
the electrical machine at the other, with 72 wires inclosed in a glass
tube connecting the two stations. He could have operated with equal
efficiency by using 37 wires having one wire for a common communicating
wire, or with 36 wires by substituting the ground for his common wire.
It does not appear that it was ever tested to any extent.
In 1798, Dr. Salva, in Madrid, constructed a similar telegraph, as that
suggested by Reizen, (see Voigt’s Magazine, vol. 11, p. 4.) The Prince
of Peace witnessed his experiments with much satisfaction, and the
Infant Don Antonio engaged with Dr. Salva in improving his instruments.
It is stated that his experiments were conducted through many miles. No
description of his plans appear to have been given to the public.
Galvanism takes its name from Galvani, Professor of Anatomy at Bologna,
who discovered it in the year 1790. As the account of the circumstances
attending the discovery of this useful and wonderful agent, may not
be uninteresting to the reader, we insert it here as related in the
“Library of Useful Knowledge.”
“It happened in the year 1790, that his wife, being consumptive, was
advised to take, as a nutritive article of diet, some soup made of
the flesh of frogs. Several of these animals, recently skinned for
that purpose, were lying on a table in the laboratory, close to an
electrical machine, with which a pupil of the Professor was amusing
himself in trying experiments. While the machine was in action, he
chanced to touch the bare nerve of the leg of one of the frogs with
the blade of the knife that he held in his hand; when suddenly the
whole limb was thrown into violent convulsions. Galvani was not present
when this occurred, but received the account from his lady who had
witnessed, and had been struck with the singularity of the appearance.
He lost no time in repeating the experiment: in examining minutely all
the circumstances connected with it, and in determining those on which
its success depended. He ascertained that the convulsions took place
only at the moment when the spark was drawn from the prime conductor,
and the knife was at the same time in contact with the nerve of the
frog. He next found that other metallic bodies might be substituted for
the knife, and very justly inferred that they owed this property of
exciting muscular contractions to their being good conductors
of electricity. Far from being satisfied with having arrived at
this conclusion, it only served to stimulate him to the farther
investigation of this curious subject; and his perseverance was at
length rewarded by the discovery, that similar convulsions might be
produced in a frog, independently of the electrical machine, by forming
a chain of conducting substances between the outside of the muscles
of the leg, and the crural nerve. Galvani had previously entertained
the idea, that the contractions of the muscles of animals were in some
way dependent on electricity; and as these new experiments appeared
strongly to favour this hypothesis, he with great ingenuity applied it
to explain them. He compared the muscles of a living animal to a Leyden
phial, charged by the accumulation of electricity on its surface, while
he conceived that the nerve belonging to it, performed the function of
the wire communicating with the interior of the phial, which would, of
course, be charged negatively. In this state, whenever a communication
was made by means of a substance of high conducting power between
the surface of the muscle and the nerve, the equilibrium would be
instantly restored, and a sudden contraction of the fibres would be the
consequence.
“Galvani was thus the first to discover the reason of that peculiar
convulsive effect which we now obtain from the Galvanic battery, and he
attributed it to a modification of electricity. It was left to another
to construct an instrument which would give a constant and increased
effect, and develop this extraordinary fluid. Whatever share accident
may have had in the original discovery of Galvani, it is certain that
the invention of the Pile, an instrument which has most materially
contributed to the extension of our knowledge in this branch of
physical science, was purely the result of reasoning.
“Professor Volta, of Pavia, in 1800, was led to the discovery of its
properties by deep meditation on the developements of electricity at
the surface of contact of different metals. We may justly regard this
discovery as forming an epoch in the history of galvanism; and since
that period, the terms Voltaism, or Voltaic electricity, have been
often, in honour of this illustrious philosopher, used to designate
that particular form of electrical agency.
“He had been led by theory to conceive that the effect of a single pair
of metallic plates might be increased, indefinitely, by multiplying
their number, and disposing them in pairs, with a less perfect
conducting substance between each pair. For this purpose he provided
an equal number of silver coins, and of pieces of zinc, of the same
form and dimensions, and also circular discs of card, soaked in salt
water, and of somewhat less diameter than the metallic plates. Of
these he formed a pile or column as shown in figure 35, in which three
substances, silver, zinc, and wet card, denoted by the letters S, Z, I,
were made to succeed one another in the same regular order throughout
the series. The efficacy of this combination realized the most sanguine
anticipations of the discoverer. If the uppermost disc of metal in
the column be touched with the finger of one hand, previously wetted,
while a finger of the other hand is applied to the lowermost disc,
a distinct shock is felt in the arms, similar to that from a Leyden
phial, or still more nearly resembling that from an electrical battery,
weakly charged. These discs are supported by two large discs, a and
i, of wood, one at the bottom and the other at the top of the pile,
with three glass rods, A, B, C, at equal distances around the pile, but
not touching it, and are cemented into the wooden base and cover. P
represents the wire connecting the silver disc, and N that connecting
the zinc.”
Fig. 35.
“The chemical agency of galvanism, exerted on fluid conductors,
placed in the circuit between the poles of the battery, is very
remarkable. Among the simplest of its effects is the resolution of
water into its two gaseous elements, oxygen and hydrogen. The discovery
of this fact is due to the united researches of Mr. Nicholson and Mr.
Carlisle, and was one of the immediate consequences of the invention
of the pile by Volta. The most convenient mode of exhibiting the
decomposition of water by the Voltaic battery, is to fill, with water,
a glass tube; to each end of which, a cork has been fitted so as to
confine the water, and to introduce into the tube two metallic wires,
by passing one, at each end, through the cork which closes it, allowing
the extremities of the wires, that are in the water, to come so near
each other as to be separated by an interval of only a quarter of an
inch. The wires being then respectively made to communicate with each
of the two poles of a Voltaic battery, the following phenomena will
ensue. If the wire connected with the positive pole of the battery
consists of an oxidable metal, it is rapidly oxidated by the water
surrounding it; while, at the same time, a stream of minute bubbles of
hydrogen gas arises from the surface of the other wire, which is in
connection with the negative pole. But if we employ wires made of a
metal which is not susceptible of oxidation by water, such as gold or
platina, gas will be extricated from both the wires, and, by means of a
proper apparatus may be collected separately.”
We shall now see that these two discoveries, viz. the Voltaic pile, and
the decomposition of water by the agency of the former are the bases of
a plan for telegraphic purposes.
Fig. 36.
“The fact that the decomposition of water may be produced with
certainty and instantaneously, not only at short, but at great
distances from the Voltaic pile, and that the decomposition may be
sustained for a considerable time, suggested to me the idea, that it
might be made subservient for the purposes of transmitting intelligence
in a manner superior to the plan in common use, and would supersede
them. My engagements were such that I have only been able to test the
practicability of my plan upon a small scale, and herewith submit, for
the Academy’s publication, an account of the experiment.
“My telegraph was constructed and used in the following manner:
In the bottom of a glass reservoir, figure 36, of which
A A is a sectional view, are 35 golden points, or pins, passing up through
the bottom of the glass reservoir, marked A, B, C, &c. 25 of which
are marked with the 25 letters of the German alphabet and the ten
numerals. The 35 points are each connected with an extended copper
wire, soldered to them, and extending through the tube, E, to the
distant station; are there soldered to the 35 brass plates, upon the
wooden bar, K K. Through the front end of each of the plates, there
is a small hole, I, for the reception of two brass pins, B and C; one
of which is on the end of the wire connecting the positive pole, and
the other the negative pole of the Voltaic column, O. Each of the 35
plates are arranged upon a support of wood, K K, to correspond with
the arrangement of the 35 points at the reservoir, and are lettered
accordingly. When thus arranged, the two pins from the column are held,
one in each hand, and the two plates being selected, the pins are
then put into their holes and the communication is established. Gas
is evolved at the two distant corresponding points in an instant. For
example, K and T. The peg on the hydrogen pole, evolves hydrogen gas,
and that on the oxygen pole, oxygen gas.
“In this way every letter and numeral may be indicated at the pleasure
of the operator. Should the following rules be observed, it will enable
the operator to communicate as much if not more, than can be done by
the common telegraph.
“First Rule. As the hydrogen gas evolved is greater in quantity than
the oxygen, therefore, those letters which the former gas represents,
are more easily distinguished than those of the latter, and must be so
noted. For example, in the words ak, ad, em, ie, we indicate
the letters A, a, e, i, by the hydrogen; k, d, m, e, on
the other hand, by the oxygen poles.
“Second Rule. To telegraph two letters of the same name, we must use
a unit, unless they are separated by the syllable. For example, the
name anna, may be telegraphed without the unit, as the syllable an,
is first indicated and then na. The name nanni, on the contrary,
cannot be telegraphed without the use of the unit, because na is
first telegraphed, and then comes nn, which cannot be indicated in
the same vessel. It would, however, be possible to telegraph even three
or more letters at the same time by increasing the number of wires from
25 to 50, which would very much augment the cost of construction and
the care of attendance.
“Third Rule. To indicate the conclusion of a word, the unit 1 must
be used. Therefore, it is used with the last single letter of a word,
being made to follow the ending letter. It must also be prefixed to
the letter commencing a word, when that letter follows a word of two
letters only. For example: Sie lebt must be represented Si, e1,
le, bt, that is the unit 1 must be placed after the first e. Er
lebt, on the contrary, must be represented. Er, 1l, eb, t1;
that is, the unit 1 is placed before the l. Instead of using the
unit, another signal may be introduced, the cross † to indicate the
separation of syllables.
“Suppose now the decomposing table is situated in one city, and the
pin arrangement in another, connected with each other by 35 continuous
wires, extended from city to city. Then the operator, with his Voltaic
column and pin arrangement at one station, may communicate intelligence
to the observer of the gas at the decomposing table of the other station.
“The metallic plates with which the extended wires are connected
have conical shaped holes in their ends; and the pins attached to
the two wires of the Voltaic column are likewise of a conical shape,
so that when they are put in the holes, there may be a close fit,
prevent oxidation and produce a certain connection. It is well known
that slight oxidation of the parts in contact will interrupt the
communication. The pin arrangement might be so contrived as to use
permanent keys, which for the 35 plates or rods would require 70 pins.
The first key might be for hydrogen A; the third key for hydrogen B;
the fourth key for oxygen B, and so on.
“The preparation and management of the Voltaic column is so well known,
that little need be said except that it should be of that durability
as to last more than a month. It should not be of very broad surfaces,
as I have proved, that six of my usual plates (each one consisting
of a Brabant dollar, felt, and a disc of zinc, weighing 52 grains)
would evolve more gas, than five plates of the great battery of our
Academy.[19]
As to the cost of construction, this model which I have had the honour
to exhibit to the Royal Academy, cost 30 florins. One line consisting
of 35 wires, laid in glass or earthen pipes, each wire insulated with
silk, making each wire 22,827 Parisian feet, or a German mile, or a
single wire of 788,885 feet in length, might be made for less than 2000
florins, as appears from the cost of my short one.”
“To the foregoing notice, we append an article published in Thompson’s
Annals of Philosophy, vol. 7, page 162, 1st series, February, 1816.
This article is from the pen of Dr. John Redman Coxe, of Philadelphia,
and it is believed that the idea of the employment of galvanism,
for a telegraph which it suggests, was then original. Those who are
acquainted with the history of the progress of electricity, as evolved
by the ordinary machine, are aware that experiments had been made with
a view to its employment for a similar purpose; but from the inherent
difficulties of the subject, the project had been abandoned.
“It is not pretended, that the state of our knowledge on the subject
of galvanism, was such at the time the foregoing suggestion was made,
as would have enabled any person to apply it practically; this, if
done, will be due to the recent discoveries on the subject of electro
magnetism; a subject which has been very successfully pursued by the
philosophers of our own country, and particularly by Professor Henry,
of Princeton. As some of the philosophers of Europe are disputing upon
the question of the authorship of proposition for the employment of
Galvanic electricity, telegraphically, we have thought that it would
not be altogether inopportune, or uninteresting, to publish the article
above referred to.
“Use of Galvanism as a Telegraph: in an extract of a
Letter from Dr. J. Redman Coxe, Professor of Chemistry, Philadelphia.
“I observe in one of the volumes of your Annals of Philosophy, a
proposition to employ galvanism, as a solvent, for the urinary
calculus, but which has been very properly, I think, opposed by Mr.
Armiger. I merely notice this, as it gives me the opportunity of
saying, that a similar idea was maintained in a thesis, three years
ago, by a graduate of the University of Pennsylvania. I have, however,
contemplated this important agent, as a probable means of establishing
telegraphic communications, with as much rapidity, and perhaps less
expense, than any hitherto employed. I do not know how far experiment
has determined galvanic action, to be communicated by means of wires;
but there is no reason to suppose it confined, as to limits, certainly
not as to time. Now, by means of apparatus, fixed at certain distances,
as telegraphic stations, by tubes, for the decomposition of water,
and of metallic salts, &c. regularly ranged, such a key might be
adopted as would be requisite to communicate words, sentences, or
figures, from one station to another, and so on to the end of the line,
I will take another opportunity to enlarge upon this, as I think it
might serve many useful purposes; but like all others, it requires
time to mature. As it takes up little room, and may be fixed in
private, it might, in many cases, of besieged towns, &c. convey useful
intelligence, with scarcely a chance of detection by the enemy. However
fanciful in speculation, I have no doubt that sooner or later, it will
be rendered useful in practice.”
“I have thus, my dear sir, ventured to encroach upon your time, with
some crude ideas, that may serve to elicit some useful experiments
in the hands of others. When we consider what wonderful results have
arisen from the first trifling experiments of the junction of a small
piece of silver and zinc in so short a period, what may not be expected
from the further extension of galvanic electricity: I have no doubt of
its being the chiefest agent, in the hands of nature, of the mighty
changes that occur around us. If the metals are compound bodies, which
I doubt not, will not this active principle combine those constituent
in numerous places, so as to explain their metallic formation? and
if such constituents are in themselves aeriform, may not galvanism
reasonably tend to explain the existence of metals in situations to which
their specific gravities certainly do not entitle us to look for them?”
From the Encyclopedia Britannica, 7th edition, page 662.
“M. Cavællo suggested the idea of conveying intelligence by passing a
given number of sparks through an insulated wire in given spaces of
time; and some German and American authors have proposed to construct
galvanic telegraphs by the decomposition of water. Mr. Ronalds, who has
devoted much time to the consideration of this form of the telegraph,
proposes to employ common electricity to convey intelligence along
insulated and buried wires, and he proved the practicability of such a
scheme, by insulating eight miles of wire on his lawn at Hammersmith.
In this case the wire was insulated in the air by silk strings. But he
also made the trial with 525 feet of buried wire; with this view he dug
a trench four feet deep, in which he laid a trough of wood two inches
square, well lined within and without with pitch; and within this
trough were placed thick glass tubes, through which the wire ran. The
junction of the glass tubes was surrounded with shorter and wider tubes
of glass, the ends of which were sealed up with soft wax.
“Mr. Ronalds now fixed a circular brass plate, figure 37,
upon the second arbour of a clock which beat dead seconds. This plate was
divided into twenty equal parts, each division being worked by a
figure, a letter, and a preparatory sign. The figures were divided into
two series of the units, and the letters were arranged alphabetically,
omitting J, Q, U, W, X and Z. In front of this was fixed another brass
plate as shown in figure 38, which could be occasionally
turned round by the hand, and which had an aperture like that shown in the figure
at V, which would just exhibit one of the figures, letters and preparatory
signs, for example, 9, v, and ready. In front of this plate was
suspended a pith ball electrometer, B, C, figure 38, from
a wire D, which was insulated, and which communicated on one side with a glass
cylinder machine, and on the other side with the buried wire. At the
further end of the buried wire, was an apparatus exactly the same as
the one now described, and the clocks were adjusted to as perfect
synchronism as possible.
Fig. 37. |
Fig. 38. |
 |
 |
“Hence it is manifest, that when the wire was charged by the machine
at either end, the electrometers at both ends diverged, and when it
was discharged, they collapsed, at the same instant. Consequently, if
it was discharged at the moment when a given letter, figure, and sign
on the lower plate, figure 37, appeared through the aperture,
figure 38, the same figure, letter and sign would appear also
at the other clock; so that by means of such discharges at one station, and by
marking down the letters, figures and signs, seen at the other, any
required words could be spelt.
“An electrical pistol was connected with the apparatus, by which a
spark might pass through it when the sign prepare was made, in order
that the explosion might excite the attention of the superintendent,
and obviate the necessity of close watching.
“Preparatory signs. A, prepare; V, ready; S, repeat sentence; P,
repeat word; N, finish; L, annul sentence; I, annul word; G, note
figures; E, note letters; C, dictionary.”
We have now to notice a discovery, which forms the basis of those
modern telegraphs in which the principle of electro magnetism is
adopted. The following is an extract from the “Library of Useful
Knowledge,” in relation to the discovery:
“The real discoverer of the magnetic properties of electric currents
M. Oersted, Professor of Natural Philosophy, and Secretary of the
Royal Society of Copenhagen. In a work which he published in the
German, about the year 1813, on the identity of chemical and electrical
forces, he had thrown out conjectures concerning the relations
subsisting between the electric, galvanic and magnetic fluids, which
he conceived might differ from one another only in their respective
degrees of tension. If galvanism, he argued, be merely a more latent
form of electricity, so magnetism may possibly be nothing more than
electricity in a still more latent form; and he, therefore, proposed it
as a subject worthy of inquiry, whether electricity employed in this,
its most latent form, might not be found to have a sensible effect
upon a magnet. It is difficult clearly to understand what he meant
by the expression of latent states, as applied to electricity, but
it may be sufficient for us to know, that in the various endeavours
he subsequently made to verify his conjectures, he was led to such
forms of experiment as afforded decisive indications of the influence
of Voltaic currents on the magnetized needle. Yet, even after he had
succeeded thus far, it was a matter of extreme difficulty to determine
the real direction of this action, and it was not till the close of the
year 1819, that his perseverance was at length rewarded by complete
success.
“The first account of his discovery that appeared in England is
contained in a paper, which he himself communicated, in Thompson’s
Annals of Philosophy, for October, 1820, vol. 16, page 273; and in
which the following experiments are described. The two poles of a
powerful Voltaic battery were connected by a metallic wire, so as to
complete the galvanic circuit. The wire which performs this office
he called the uniting wire; and the effect, whatever it may be,
which takes place in this conductor, and in the space surrounding
it, during the passage of the electricity, he designates by the term
electric conflict, from an idea that there takes place some continued
collision and neutralization of the two species of electric fluids,
while circulating in opposite currents in the apparatus. Then taking a
magnetic needle, properly balanced on its pivot, as in the mariner’s
compass, and allowing it to assume its natural position in the magnetic
meridian, he placed a straight portion of the uniting wire horizontally
above the needle, and in a direction parallel to it; and then completed
the circuit, so that the electric current passed through the wire.
The moment this was done, the needle changed its position, its ends
deviating from the north and south towards the east and west, according
to the direction in which the electric current flowed, so that by
reversing the direction of the current the motion of the needle was
also reversed. The general law he expressed as follows: ‘That end of
the needle which is situated next to the negative side of the battery,
or towards which the current of positive electricity is following,
immediately moves to the westward.’
“The deviation of the needle is the same, whether the uniting wire,
instead of being immediately above the needle, be placed somewhat to
the east or west of it, provided it continue parallel to and also above
it. This shows that the effect is not the result of a simple attractive
or repulsive influence, for the same pole of the magnetic needle which
approaches the uniting wire, when placed on its east side, recedes from
it when placed on its west side.”
[20]
“Soon after this important discovery of Oersted’s was made, M.
Ampère established the second fundamental law of electro magnetism,
that the two conducting wires from the poles of the battery, when
conveniently suspended, attracts each other when they transmit
electrical currents moving in the same direction, and repel each other
when the currents which they transmit have opposite directions.
“On the 25th Sept. 1820, M. Arago communicated to the French Institute
the important discovery that the electrical current possesses, in a
very high degree the power of developing magnetism in iron or steel.
Sir H. Davy communicated a similar fact to Dr. Wollaston on the 12th of
November, 1820, and Dr. Seebeck laid before the Royal Academy of Berlin
a series of experiments on the same subject.
“M. Arago found that the uniting wires of a powerful Voltaic battery
attracts iron filings often with such force as to form a coating around
the wire ten or twelve times thicker than itself. This attraction, as
he found, did not originate in any magnetism previously possessed by
the iron filing, which he ascertained would not adhere to iron, and
that it was not a case of common electrical attraction, was evident
from the fact that copper and brass filings were not attracted by the
uniting wire. M. Arago likewise found, that the iron filings began to
rise before they came in contact with the uniting wire; and hence he
drew the conclusion, that the electric currents converted each small
piece of iron into a temporary magnet. In following out this view,
the French philosopher converted large pieces of iron into temporary
magnets and also small steel needles into permanent ones, (by employing
the helix.) Sir H. Davy and Dr. Seebeck obtained analogous results
without knowing what had been previously done in France.
“A galvanometer was first constructed by Professor Schweigger, of
Halle, very soon after the first discovery of electro magnetism, and by
him called an electro magnetic multiplier.”
In the year 1820, Ampère predicted the possibility of making the
deflection of the magnetic needle, by the agency of the galvanic fluid,
serve the purposes of transmitting intelligence. In page 19 of his
memoir, he thus resolves the problem:
“As many magnetic needles as there are letters of the alphabet,” he
says, “which may be put in action by conductors; which may be made
to communicate successively with the battery by means of keys; which
may be pressed down at pleasure, might give place to a telegraphic
correspondence which would surmount all distance and would be as prompt
as writing speech to transmit thought.”
“The next step in the progress of discovery, was that of making magnets
of extraordinary power by means of a galvanic battery. This seems to
have been first accomplished by Prof. Moll, of Utrecht, and Professor
Henry, of Princeton, who was able to lift thousands of pounds weight by
his apparatus.”
“In the very early stage of electro magnetic experiments, it had been
suggested, that an instantaneous telegraph might be constructed by
means of conjunctive wires, and magnetic needles. The details of this
contrivance are so obvious, and the principles on which it is founded
so well understood, that there was only one question which could render
the result doubtful. This was, whether by lengthening the conjunctive
wires, there would be any diminution in the electrical effect upon the
needle. It is the general opinion, that the electrical fluid, from a
common electrical battery, may be transmitted, without any sensible
diminution, instantaneously, through a wire three or four miles in
length. At the philosophical dinner, as it has been called, got up a
number of years ago by some gentlemen of Philadelphia, on the banks of
the Schuylkill, it may be recollected that Dr. Franklin killed a turkey
with the electric shock, transmitted across the river, a distance of
more than half a mile; and Dr. Watson, who was also at the pains of
making some experiments of this kind, asserts that the electric shock
was transmitted, instantaneously, through the length of 12,276 feet.
Had it been found true that the galvanic fluid could be transmitted in
a moment through a great extent of conducting wire, without diminishing
its magnetic effect then no question could have been entertained as
to the practicability and importance of the suggestion adverted to
above, with regard to the telegraph. Mr. Barlow, of the Royal Military
Academy, who has made a number of successful experiments and
investigations in electro magnetism, fully ascertained that there was
so sensible a diminution with only 200 feet of wire, as to convince him
at once of the impracticability of the scheme.
[21]
“In 1828, M. Victor Triboaillet de Saint Amand proposed to establish
a correspondence from Paris to Brussels, by placing along the highway,
and at some feet deep, a metallic wire, about a line or a line and
a half diameter. He recommended to cover the wire with shellac, upon
which was to be wound silk, very dry, which should be covered in their
turn with a coating of resin. The whole was then to be put into glass
tubes carefully luted up with a resinous substance and secured by
a last envelope in the earth, then varnished over and hermetically
sealed. Then, by means of a powerful battery, he would communicate the
electricity to the conducting wire, which would transmit the current
to the opposite point to an electroscope, destined to render sensible
the slightest influence, and left to each one to adopt at pleasure the
number of motions to express the words or letters which they might need.”
“Fechner, in his manual of galvanism, (Voss, 1829, page 269,) remarked,
that the electro magnetic effects of the galvanic current would be far
more appropriate for the giving of signs than Soemmering’s plan by the
decomposition of water.”
He suggested that wires, having twenty-four multiplicators should be
extended between Leipsic and Dresden, and there connected, alternately,
with a galvanic column, for telegraphic purposes. Indeed, he ventured
to prophecy, that probably hereafter such a connection between the
central point of a kingdom, and different provinces might be arranged
as there was existing in animal bodies, between the central point of
organic structure of particular members and nerves.
We come now to give an account of a new branch in the science of
electricity, viz. magneto electricity; which Dr. Faraday was the
first to discover in the year 1831. As this species of electricity has
been applied to several of the plans of electric telegraphs, which we
shall describe, it is desirable that some account should be given of
its discovery, and of the instrument by which it is generated.
The following is an extract from “Daniell’s Introduction to Chemical
Philosophy” 2d edition, London, 1843.
“The phenomena of electro magnetism are produced by electricity in
motion; accumulated electricity, when not in motion, exerts no
magnetic effects. Dr. Faraday early felt convinced that “as every
electric current is accompanied by a corresponding intensity of
magnetic action at right angles to the current, good conductors of
electricity, when placed within the sphere of this action, should have
a current induced through them, or some sensible effect produced,
equivalent in force to such a current.” These considerations, with
their consequence, the hope of obtaining electricity from ordinary
magnetism, stimulated him to investigate the subject experimentally,
and he was rewarded by an affirmative answer to the question proposed.
He thus became, like Oersted, the founder of an entirely new branch of
natural philosophy.
“If a wire connecting the two ends of a delicate galvanometer be
placed parallel and close to the wire connecting the poles of a
Voltaic battery, no effect will be produced upon the needle, however
powerful the current may be. If the points opposed in the two wires be
multiplied by coiling the one, as a helix, within the convolutions
of the other, coiled in the same way, both being covered with silk to
prevent metallic contact, still no effect will be discernible so long
as the current is uninterrupted. When, however, the current of the
battery is stopped by breaking the circuit, the needle is momentarily
deflected, as by a wave of electricity passing in the same direction
as that of the main current. Upon allowing the needle to come to a
state of rest, and then renewing the contact, a similar impulse will
be given to it in the contrary direction. While the current continues,
the needle returns to its state of rest, again to be deflected in the
first direction by stopping the current. Motion may be accumulated to a
considerable amount in the needle, by making and breaking the contacts
with the battery in correspondence with its swing. The same effects are
produced when, the current being uninterrupted, the conducting wire is
made suddenly to approach or recede from the wire of the galvanometer.
As the wires approximate, there will be a momentary current induced
in the direction contrary to the inducing current; and as the wires
recede, an induced current in the same direction as the inducing
current.
“As this Volta electric induction is obviously produced by the
transverse action of the Voltaic current, in one case, by the
mechanical motion of the wire, and in the other at the moments of
generation and annihilation of the current, Dr. Faraday thought
that the sudden induction and cessation of the same magnetic force in
soft iron, either by the agency of a Voltaic current, or by that of
a common magnet, ought to produce the same results. He constructed
a combination of helices (8) upon a hollow cylinder of pasteboard:
they consisted of lengths of copper wire, containing, altogether,
220 feet; four of these were connected end to end, and then with the
galvanometer. The other intervening four were also connected end to
end, and then with the Voltaic battery. In this form a slight effect
was produced upon the needle by making and breaking contact. But
when a soft iron cylinder, seven-eighths of an inch thick and twelve
inches long, was introduced into the pasteboard tube, surrounded by
the helices, the induced current affected the galvanometer powerfully.
When the iron cylinder was replaced by an equal cylinder of copper, no
effect beyond that of the helices alone was produced.
“Similar effects were then produced by ordinary magnets. The hollow
helix had all its elementary helices connected with the galvanometer,
and the soft iron cylinder having been introduced into its axis, a
couple of bar magnets were arranged with their opposite poles in
contact, so as to resemble a horse-shoe magnet, and contact was then
made between the other poles and the ends of the iron cylinder, by
which it was converted, for the time, into a magnet; by breaking
the magnetic contacts, or reversing them, the magnetism of the iron
cylinder could be destroyed or reversed at pleasure. Upon making
magnetic contact, the needle was deflected; continuing the contact,
the needle became indifferent, and resumed its first position; on
breaking contact, it was again deflected, but in the opposite direction
to the first effect, and then it again became indifferent. When the
magnetic contacts were reversed, the deflections were reversed. The
actual contacts of the magnets with the soft iron is not essential
to the success of these experiments, for their near approximation
induces sufficient magnetism in the cylinder to generate the electric
current, which affects the needle. The first rise of the magnetic
force induces the electric wave in one direction; its sudden decline,
in the opposite. Mechanical motion of a permanent magnetic pole in
one direction, across the coils of the helix, will produce the same
effect as the sudden induction of the magnetism in the soft iron, and
its motion in the opposite direction will cause a corresponding effect
with its annihilation, when the soft iron cylinder is removed from the
helix, and one end of a cylindrical magnet thrust into it, the needle
is deflected in the same way as if the magnet had been formed, by
either of the two preceding processes. Being left in, the needle will
resume its first position, and then being withdrawn, the needle will be
deflected in the opposite direction. On substituting a small hollow
helix, formed round a glass tube, for the galvanometer, in these
experiments, and introducing a steel needle, it will be converted into
a magnet, provided care be taken not to expose it to the opposite
action of the reverse current; and if the continuity of the conducting
wire be broken, at the moment when the secondary electric wave is
passing through it, a bright spark may be obtained.
“The connection of electro magnetical and magneto electrical phenomena
may be exhibited in a very striking way, by employing any of the
apparatus, by which the rotary motions of the magnet or conducting
wire, are produced by a current of electricity, to generate electric
currents by the mechanical rotations of the magnet or wire. For this
purpose, the galvanometer may be substituted for the battery, and
when the wire is made to turn round the pole of the magnet, or the
pole of the magnet round the wire, in one direction, the needle will
be deflected to one side; and to the other by the opposite rotation.
Nothing can be better shown that magneto electric is the converse
of electro magnetic action.
“Dr. Faraday by rotating a copper disc between the poles of a
horse-shoe magnet, produced a constant current of electricity in one
direction, and deflected the needle of the galvanometer; one wire being
connected with the disc, and the other with the arbour. By turning
the disc in one direction, the circuit will pass from the axis to the
circumference; by turning it in the opposite direction, the current
will flow from the circumference to the axis.”
Fig. 39.
Figure 39 represents a side view of the instrument. B shows
the copper disc permanently secured upon its axis, and which is turned by means of
the crank, E. G represents one of the standards which support the
axis. H is the platform upon which the various parts are arranged. The
edge, C, of the copper disc, is amalgamated so as to make a perfect
connection with the amalgamated segment, a, to which is soldered a
wire, I, leading to the galvanometer. That portion of the disc, B,
which is shaded, is not amalgamated. J is the other wire proceeding
from the galvanometer, and both it and the axis are amalgamated, at the
points of connection. A is the permanent magnet, with its poles on each
side of the copper disc, B, opposite the amalgamated portion of the rim.
Fig. 40.
Figure 40, represents a top view of the instrument,
H is the platform; C the disc; a the segment; A the permanent magnet;
J the wire attached to the axis, P; G and G are the two standards. E the crank;
and I the wire attached to the segment a.
Mr. Saxton,[23] in a letter to Mr. Lukens, dated, London, April 14th,
1832, after describing Dr. Faraday’s rotating disc,
figures 39 and 40,
says, “I have made this experiment in a different way, and succeeded
satisfactorily. The method was as follows: A coil of wire wrapped
with silk, similar to that used in the galvanometer, was attached,
by the ends, to the wires of the galvanometer. On passing this roll,
backward and forward, upon one of the poles of a horse-shoe (permanent)
magnet, or placing it upon and removing it from either pole, I have
made the needle of the galvanometer to spin round rapidly.” Figure 41,
represents Mr. Saxton’s plan.
Fig. 41.
N and S represent the north and south poles of the horse-shoe permanent
magnet. C is the coil of wire, wound round a spool of an oblong shape,
through the centre of which there is an opening sufficiently large
to admit either of the prongs of the magnet through it. A and B are
the ends of the wire leaving the coil, and are connected with the
galvanometer.
Mr. Saxton on the 2d of May, 1832, obtained the spark
by the following arrangement of the permanent magnet and the helix of wire round the
armature. In relation to this instrument, he thus writes to Mr. Lukens,
of Philadelphia, dated, London, May 11th, 1832. Jour. Frank. Int. vol.
13, p. 67. “Since my last I have heard of a method of producing a spark
from a magnet, discovered I think by an Italian.[24]
This experiment I made at once upon a large horse-shoe magnet, which I
am making for Mr. Perkins and his partners. One of your large magnets
will answer the same purpose. Make a cylinder of soft iron of an inch,
or three-fourths of an inch, in diameter, and of the usual length of
the keeper; place two discs of brass or wood upon this cylinder, and
at such a distance apart that they will conveniently pass between the
poles of the magnet; between these wind, say fifty feet of bobbin wire,
which may be of iron covered with cotton; let the ends of this coil be
bent over the ends of the cylinder and brought down until they touch
the poles of the magnet. The ends should be of such a length, that on
bringing the cylinder to the magnet, one of the ends will touch, when
the cylinder is about half an inch from the magnet, and the other at
one-fourth of an inch. The cylinder being thus arranged, and in contact
with the magnet, on drawing it suddenly away a spark will pass between
the end of the wire, and the pole of the magnet.”
Fig. 42.
Figure 42 represents the instrument as first constructed by Mr.
Saxton, in London.[25]
A and B are the ends of the helix, surrounding the cylindrical bar of
soft iron between E and F, filling the cavity which has been formed
out of the solid iron. The size of bar between the collars E and F,
thus formed, is the same as the projections H and G. The wire, a,
proceeds from the outside of the coil and makes a suitable contact upon
the prong, A, of the magnet: b proceeds from the bottom of the coil,
where the winding commenced and makes a similar contact upon the prong,
B, of the permanent magnet. One wire extends a little further upon the
magnet than the other, so that the shorter one may break its connection
sooner than the longer. H and G are projections from the sides of the
armature, to which the handle, D, is secured. Let the armature, with
its helix, be held up against the ends of the prongs of the permanent
magnet; and the wires a and b, in perfect contact with their
respective prongs, as shown in the figure; if, while in
this condition, the keeper is suddenly withdrawn, a spark will appear at the end
of the short wire, as it breaks its contact with the prong of the magnet.
Mr. Saxton, however, was still further successful, the following year,
in carrying out an idea which occurred to him on the 6th of December,
1832, of producing the same phenomena, with a more convenient and
powerful rotating instrument.[26]
This new arrangement he was able to test on the 20th of June, 1833,
and obtained the spark. On the 22d, he made an unsuccessful attempt,
in the presence of Prof. Rogers, of Philadelphia, at the decomposition
of water. On the 30th of June he exhibited it at a meeting of the
British Association at Cambridge, before Dr. Faraday, Dr. Brewster,
Prof. Forbes, Dr. Dalton, and many other distinguished and scientific
gentlemen. The experiments made by it were the exhibition of the spark,
giving shocks, &c. On the third of July, Mr. Saxton succeeded in
decomposing water, by adding a little sulphuric acid, and on the 25th
of August, he ignited and melted platinum wire.
Fig. 43.
Figure 43 exhibits a side view of the instrument:
a, a, a, is a compound permanent magnet, consisting of three
steel plates, put together, side by side. B and C are two wooden supports, upon the
platform A A. To these supports the magnet is permanently secured, by a
yoke, S, through which pass two screws into the wooden supports below.
M is a cross bar, into which, and at right angles with it, are screwed
two arms of round soft iron, R, about five-eighths of an inch in
diameter, the whole forming the armature or keeper of the magnet. Upon
these two projecting arms, are placed two coils, D′ and D, of copper
wire, insulated with silk. The whole is very securely fastened upon
the steel spindle, N, which has its journals in the supports, B and
B′. On the end of the spindle, N, near the curve of the magnet, there
is a small band pulley, F, which is driven by the band or cord of the
large wheel, E, and the crank, J. The axis of the large wheel passes
through a long socket, L, in the top of the column, H; on one end of
the axis the band wheel is fastened and on the other the crank. By this
arrangement a very rapid and quiet rotary motion is given to the armature.
In the column, H, there is a socket, into which the stem of the upper
part of the column, G, is fitted, which admits of the large wheel being
raised or lowered, so as to prevent the band from slipping, and when
properly adjusted it is secured by the screw, I. O is an ivory hub,
sliding over that part of the spindle immediately projecting beyond
the cross bar, M. Upon this ivory hub is a copper disc, C, with a
socket, n: b, is a needle made of platinum, which, with its socket,
m, is nicely fitted upon the end of the steel spindle, so as to be
adjusted to any required angle with the armature, and when adjusted
to retain its position. The two ends of the two coils, which leave
the centre of the helices, are made to form a contact with the soft
iron arms, R R, passing through the coils, D′ and D, thus making the
circuit complete with the needle b, upon the end of the spindle, N,
by a continuous metallic connection of the arms, with the cross bar,
M, and through the cross bar to the spindle, N, in contact with the
needle, b. The two ends of the two coils, leaving the outside of
the helices, are joined in one, and as they pass through the cross bar,
M, are insulated from it, by a piece of ivory, inserted in the cross
bar. The united wire then passes into and through the ivory hub, e,
forming a perfect contact with the copper disc, c, underneath its
socket, n: d, is a cup of mercury, in which the copper disc, c,
is always immersed, and the needle, b, twice in every revolution of
the armature. The cup, d, is so constructed as to rise and fall, by
means of a stem, i, sliding vertically into a socket, e, of its
support, and is secured to its position by the screw, h. In this way,
its proper height for breaking and closing the circuit may be easily
obtained, when the armature is rotating. The proper position for the
needle, b, is that in which it is just leaving the mercury, as the
keeper arrives at the position, in which its magnetism is neutralized.
This position is seen at X, where D″ and D′ are the sides of the
coils; c the copper disc; m the cross bar of the armature; R the
arm passing through the coil; and b the needle, at that angle which
it requires, when the armature is vertical or at its neutral position.
It will be observed that the needle is just leaving the mercury, d.
Fig. 44.
Figure 44 represents a top view. N and S represent the
north and south poles of the permanent magnet. N′ and N′ is the spindle, parallel with
the prongs of the magnet, and equidistant from them; L is the socket
of the band wheel; D′ and D the horizontal position of the coils; M is
the cross bar; b the needle; c the copper disc, and m and n
their respective sockets; o the ivory hub; d the cup of mercury; A
the platform; and S′ and S′ the yoke through which pass two screws to
secure the magnet to the wooden support below.
When the armature is made to rotate, it becomes a temporary magnet, by
the laws of magnetic induction, whenever the arms carrying the helices
come opposite to the poles of the permanent magnet, and when these soft
iron arms have reached the point at right angles to the magnet,
or vertical, their magnetism for an instant is destroyed, and are as
instantaneously reversed from what they were before reaching that
point. They are also magnetic, just in that proportion as they recede
from or approach to the poles of the permanent magnet.
Hence, first, one arm is the south pole, when opposed to the north
pole of the magnet; and the other arm a north pole, when opposed to
the south pole of the magnet. But when they have made a half revolution
on their axis, from their first position, their magnetism is reversed.
The arm which was a south pole, has become a north pole; and the arm
that was a north pole has become a south pole. Thus, by the rotation
of the armature, direction of the induced current in the arms, become
changed, as often as they are alternately brought opposite the poles of the
permanent magnet, which is twice in every revolution of the armature.
It follows, then, by the laws of magneto induction, that as often as
the arms become magnetic, they induce corresponding opposite electric
currents in the wire surrounding those arms, provided the circuit
of the coils is complete. The disc, which is in metallic connection
with two ends of the wire leaving the coils, (one from each coil,) is
always immersed in the mercury of the cup. The needle, however, which
is in connection with the other two wires from the two coils, (one from
each coil,) is not always immersed, but only when the armature is at
a certain position in relation to the permanent magnet. The circuit
then can only be closed when the needle is immersed, as well as the
disc. Upon inspecting the figure, it will be found that
the needle is immersed at the time the arms are passing the poles of the magnet,
and that when they arrive at the vertical or neutral position, the needle
has just broken its connection with the mercury, and at that instant
the spark is observed.
Professor Daniell observes, that “by means of this magneto electrical
machine, all the well known effects of Voltaic currents may be very
commodiously produced. When the communication is made between the
spindle and the revolving disc, by means of a fine platinum wire,
instead of the dipping points, the wire may be maintained at a red
heat; although the effect being produced by alternating currents in
opposite directions, a kind of pulsation, or intermission of the
light, may be discerned. Upon making the communication between the two
mercury cups, by means of copper cylinders grasped in the hands, a
continued painful contraction of the muscles of the arm takes place,
which destroys voluntary motion, and, under certain circumstances, is
perfectly intolerable.
“The general expression of these phenomena may be thus stated: whenever
a piece of metal is passed, either before a single pole, or between the
opposite poles of a magnet, or before electro magnetic poles, whether
ferruginous or not, so as to cut the magnetic curves, (or lines, which
would be marked out by a spontaneous arrangement of iron filings,)
electrical currents are produced across the metal, transverse to the
direction of motion.”
This important instrument also depends, for its action, upon the
principle discovered by Dr. Faraday, that electricity was developed in
conducting bodies, when they were moved in a certain direction, in the
neighbourhood of permanent magnets. Since the beautiful and ingenious
invention which Mr. Saxton was the first to make, no valuable improvements
have been made in this machine, except those introduced by Professor Page.
The first important change in the machine, was the adaptation of his
pole changer to the machine, in place of the break pieces, which were
used in all the modifications up to that time; and another equally
useful improvement, consisted in the arrangement of the permanent
magnets and armatures. Previous to this last improvement, these
machines were constructed with a single permanent magnet, and one or
more revolving armatures, necessarily involving great disadvantages.
Page’s improvements were completed in February, 1838, and shortly after
published in Silliman’s Journal. He was also the first to suggest the
combination of several machines under one mechanical movement, as the
best mode of augmenting power in this way.
The combined machine, described in Daniell’s Introduction to Chemical
Philosophy, as invented by Wheatstone, about two years since, is the
same as that described, and represented by Dr. Page in Silliman’s
Journal in 1838. In the same publication, Dr. Page described the
arrangement of the permanent magnets and armatures, as shown in
the annexed figures. The adaptation of the pole changer, which, in
connection with this machine, is called the Unitrep, Dr. Page has
given to the public. But as he has never allowed the improvement, which
consists in the use of two or more permanent magnets and straight
armatures, to be sold with his knowledge and consent, he intends to
claim a patent for the same; it having been decided by our courts,
that the publication of an invention by the inventor, does not affect
his right to a patent, provided he does not allow the invention to be
sold and used.
The figures 45, 46 and 47, exhibit one of Page’s machines with his
early improvements.
Figure 45, is a side elevation of the machine.
Figure 46, is a top view.
Figure 47, are views of the revolving armatures and coils.
In Figure 45, representing a side view of the machine,
B and B are the compound permanent steel magnets, composed of six bars each of the U
form, mounted upon the brass pillars, P, P, P, P, which are fastened
into the common platform of the whole machine. Through the platform
there pass stout rods, R and R, and upwards through two brass straps,
above the magnets, B and B. These straps or yokes secure the magnets
from any motion by means of the screw nuts. A is a circular case of
pasteboard, containing the armatures and coils. H is a band wheel
surrounding the case, for mechanical connection with any source of
power that may be used to keep the machine in motion. I′ and I are two
metallic studs, with an aperture passing vertically from the top, to
the depth of an inch, for the reception of connecting wires, and then,
by means of a screw at its side, to make a perfect contact. There
are two other studs directly behind them. G and J are the two pulley
wheels, with their band and crank, by which a rapid rotary motion is
given to the armatures and coils. These pulleys are supported by the
standard. From the bottom of the studs I′ and I, as also from those
directly behind them, proceed wires which are carried along below
the platform, and pass up through it between the pilliar, P, and the
revolving armatures, to the shaft; there being one on each side of the axis.
Fig. 45.
Fig. 46.
Figure 46, represents a top view of the instrument.
A is the case containing the armatures and coils, and H the band wheel. N, S and N,
S, are the north and south poles of the permanent magnets. S′ and S′
are the yokes by which the magnets are secured to the platform, and the
screws near the poles of the magnets are for the purpose of setting
the magnets to any required position, laterally, and securing them in
it. M and M are the tops of the two pilliars, which support the shaft
of the armatures and coils. The bearings are so made as to allow the
apparatus to revolve with as little friction as possible: 3 and 3
represent the set screws against the ends of the shaft, for adjusting
the ends of the permanent magnets; by which means, the armatures may
be allowed to pass very near the ends of the magnets without touching.
6, 7, 8, and 9 are the receiving studs, by which the wires from any
other instrument may be connected with the machine. The wire, a, in
contact with the unitrep, as before stated, is continued and soldered
to the receiving stud, 6; in the same manner, c, also in contact
with the unitrep, is connected with 7; and also 3 with 8; and a with
9. The manner in which these wires, a, c, 3, and a, form their
contact with the shaft, is seen at N and P, figure 45,
of which 5 and 5 represent a section of the shaft and unitrep.
Fig. 47.
Figure 47 represents the revolving armatures and coils,
with the case taken off. C and C are the two coils of insulated copper wire,
surrounding two straight bars of soft iron, represented in the end view
by D and D. E is the shaft. The two armatures and coils are secured to
the two brass straps F, which are themselves fastened upon the shaft.
The armatures are allowed to project through the straps about the
sixteenth of an inch.
On each end of the shaft is attached an unitrep, consisting of
two cylindrical segments of silver, as seen at 5 and 5, figure 45;
insulated from each other, and secured to a cylinder of ivory or
wood, upon the shaft, so as to revolve with it. The terminations of
the coils of wire upon the armatures, are soldered to the segments
of silver, and as the unitrep turns, it brings opposite ends of the
wires, alternately, upon the stationary wires or conductors, P and N:
(in figure 46 they are represented by a and c,
and 3 and a.) The opposing currents of the coils, in each half revolution, are,
by this contrivance, made to form one continuous current. Hence, the
name unitrep (to turn together.) There being two unitreps, and
corresponding conducting wires, and screw cups, the induced currents
from the two coils may be combined in several ways, after the manner of
combining separate batteries.
Let the wires below the base board be all properly connected with the
receiving cups, as heretofore described. Then let the wire from 6,
(represented by dots,) to k, be connected with the wire 9 and m;
and also the wire 7 and l, with the wire 8 and 0. Let one of the
united wires be connected with one wire leaving the coil of an electro
magnet; and the other united wire be joined to the other wire of the
electro magnet of the telegraph, or any other instrument designed to
operate by a galvanic battery. When this preparation is finished,
if the armatures and coils are made to revolve rapidly, a powerful
current is formed in the induced coils, C and C, figure 47,
capable of performing all the experiments generally made by means of
the galvanic battery.
Dr. Page has made a very important discovery in connection with this
machine, not now to be made known; but, suffice it to say, the single
machine which he has now in his possession, on Christmas day, 1844,
operated Morse’s telegraph, through the circuit of 80 miles; half
this circuit being wire, the other half the earth. This machine makes
an electro magnet sustain 1000 pounds, and melts a platinum wire
one-fortieth of an inch in diameter.
We introduce here a description of an instrument used for reversing
the direction of the galvanic current, and which is applied in the
operation of several kinds of electric telegraphs. There is a variety
of modes by which the same object is attained, but as this appears the
most simple, we have chosen it in preference to others.
The following figures, 48, 49
and 50, are three views of the instrument
as it appears when looking down upon it, in its three changes. First,
that in which the current is broken and the needle vertical. Second,
in which the circuit is closed and the needle deflected to the right.
Third, in which the circuit is closed and the needle deflected to
the left. Each figure has, in connection with the pole changer, the
battery, or any other generator of the electric fluid, represented by N
and P, and the galvanometer represented by G. In each of the figures,
the circles numbered 1, 2, 3, 4, 5, 6, 7, and 8, represent cups, filled
with mercury, let into the wood of the platform, and made permanent.
The small parallel lines terminating in these cups, represent copper
wires or conductors.
Fig. 48.
A, figure 48, represents a horizontal lever of wood,
or some insulating substance, with its axis supported by two standards, B and C,
by which it can easily vibrate. D represents an ivory ball, mounted upon a
rod, inserted in the lever, and extending a few inches above it. It
serves as a handle, by which to direct the elevation or depression of
either end of the lever. Both ends of the lever branch out, presenting
two arms each. Through each arm passes a copper wire, insulated from
each other. The left hand branches support the wires which connect
the mercury cups, 1 and 4, and 2 and 3, together. The right hand
branches support the wires which connect the cups 5 and 7, and 6 and
8, together. The ends of these wires directly over the mercury cups
are bent down, so that they may freely enter their respective vessels
when required. The other wires are permanently secured to the platform.
The position of the lever is now horizontal, and the bent ends of
the wires, which it carries, are so adjusted, that none of them touch
the mercury, consequently, there is no connection formed between the
battery and galvanometer, and the needle is vertical. The ivory ball,
it will be observed, is directly over the centre of the axis, and in
that position required to break the circuit. Thus, the wires, 2 and 3,
1 and 4, 5 and 7, 6 and 8, are each out of the mercury, and the circuit
being broken the fluid cannot pass.
Fig. 49.
Figure 49 represents those connections which are formed
when the left hand side of the lever is depressed, immersing in the mercury those
wires supported by it. The ball and lever are omitted for the better
inspection of the wires. Now the circuit is closed, and the current
is passing from P, of the battery, to the mercury cup, 1; then along
the cross wire to 4; to 8; to the coils of the multiplier, deflecting
the needle to the right; then to 7; to 3; then along the cross wire,
(which is not in contact with wire 1 and 4,) to 2; to the N pole of the
battery. The arrows also show the direction of the current. It will be
observed that the cups 5 and 7, and 6 and 8 are not now in connection, and
consequently the current cannot pass along the wires 1 and 5, and 2 and 6.
Fig. 50.
Now, if the ball, D, is carried to the right, a new set of wires,
figure 50, are immersed, and those
represented in figure 49, as in
connection, are taken out of their cups. The fluid now passes from P,
of the battery, to the mercury cup, 1; to 5; to 7; to the coils of the
multiplier, deflecting the needle to the left; then it passes to
cup 8; to 6; to 2; and then to the N pole of the battery; the arrows
representing the direction of the current. It will now be found, that
the cups, 2 and 3, and 1 and 4 are not in connection, and consequently
the current cannot pass along the wires, 3 and 7, and 4 and 8.
Thus, it will appear, that by carrying the ball, D, to the left, the
needle is deflected to the right; then, by carrying the ball to the
right, the needle is deflected to the left; and that when the ball is
brought to the vertical position, the needle is vertical. These three
changes enter into the plans of several electric telegraphs, which are
to be hereafter described.
To our readers the principles and arrangement of Morse’s telegraph have
been fully explained in the former part of this work. We shall here
present some of the evidence of the time of its invention.
Extract from a letter from S. F. B. Morse to the
Hon. Levi Woodbury, Secretary of the Treasury,
dated Sept. 27th, 1837.
“About five years ago, on my voyage home from Europe, the electrical
experiment of Franklin, upon a wire some four miles in length, was
casually recalled to my mind, in a conversation with one of the
passengers, in which experiment it was ascertained that the electricity
travelled through the whole circuit in a time not appreciable, but
apparently instantaneous. It immediately occurred to me, that if
the presence of electricity could be made visible in any
desired part of this circuit, it would not be difficult to construct a
system of signs by which intelligence could be instantaneously
transmitted. The thought, thus conceived, took strong hold of my mind,
in the leisure which the voyage afforded, and I planned a system of
signs and an apparatus to carry it into effect. I cast a species of
type, which I had devised for this purpose, the first week after my
arrival home; and although the rest of the machinery was planned, yet,
from the pressure of unavailable duties, I was compelled to postpone my
experiments, and was not able to test the whole plan until within a few
weeks. The result has realized my most sanguine expectations.”
The following letters were published in the Journal of Commerce, from
the originals now in possession of Prof. Morse.
Letter of the Hon. W. C. Rives.
Senate Chamber, September 21st, 1837.
My Dear Sir,—I hope you will find in my
multiplied and oppressive engagements here, an apology for not having
sooner answered your inquiry on the subject of your Electro Magnetic
Telegraph. I retain a distinct recollection of your having explained
to me the conception of this ingenious invention, during our voyage
from France to the United States in the year 1832, and that it was,
more than once, the subject of conversation between us, in which I
suggested difficulties which you met and solved with great promptitude
and confidence.
I beg leave to assure you, that it would give us all great pleasure
to renew, in personal intercourse at home, the agreeable souvenirs of
our acquaintance, and friendly relations abroad.
I remain with great respect,
Your most obd’t serv’t,
W. C. RIVES.
Prof. S. F. B. Morse.
Letter of Capt. William W. Pell,
of the packet ship Sully.
New York, Sept. 27th, 1837.
Dear Sir—On my arrival here I received your
letter, calling upon my recollection for what was said on
the subject of an electric telegraph, during the passage
from Havre, on board of the ship Sully, in October, 1832.
I am happy to say, I have a distinct remembrance of your
suggesting, as a thought newly occurred to you, the
possibility of a telegraphic communication being effected
by electric wires. As the passage progressed, and your
idea developed itself, it became frequently a subject of
conversation. Difficulty after difficulty was suggested
as obstacles to its operation, which your ingenuity still
labored to remove, until your invention, passing from its
first crude state through different grades of improvement,
was, in seeming, matured to an available instrument, wanting
only patronage to perfect it, and call it into reality; and
I sincerely trust that circumstances may not deprive you
of the reward due to the invention, which, whatever be its
source in Europe, is with you at least, I am convinced,
original.
When you observed to me a few days before leaving the ship, “well,
Captain, when you hear of the telegraph one of these days, as the
wonder of the world, remember the discovery was made on board the good
ship Sully,” I, then, little thought, I should ever be called upon to
throw into the scale, my mite of testimony in support of your claims to
priority of invention, for what seemed so startling a novelty.
With my respects and best wishes,
I subscribe myself,
WILLIAM W. PELL.
Samuel F. B. Morse, Esq.
A subsequent letter from Captain Pell, dated February 1st, 1838, after
having seen the operation of the telegraph at the University, has the
following paragraph:
“When, a few days since, I examined your instrument, I recognized in
it the principles and mechanical arrangements, which, on board, I had
heard you so frequently explain through all their developments.”
From a letter now in possession of the author, and addressed to him by
Prof. Morse, we make the following extract:
“In 1826, the lectures, before the New York Atheneum, of Dr. J. F.
Dana, who was my particular friend, gave to me the first knowledge
ever possessed of electro magnetism; and some of the properties of
the electro magnet; a knowledge which I made available in 1832 as
the basis of my own plan of an electro telegraph. I claim to be the
original suggestor and inventor of the electric magnetic telegraph,
on the 19th of October, 1832, on board the packet ship Sully, on my
voyage from France to the United States, and, consequently, the
inventor of the first, really practicable telegraph on the electric
principle. The plan then conceived and drawn out in all its essential
characteristics, is the one now in successful operation. All the
telegraphs in Europe, which are practicable, are based on a different
principle, and, without an exception, were invented subsequently
to mine.
“The thought occurred to me, in a general conversation, as seated at
the table with the passengers, in which the experiments of Franklin
to ascertain the velocity of electricity through three or four miles.
The thought at once occurred to me that electricity might be made the
means of conveying intelligence, and that a system of signs might
easily be devised for the purpose. I ought, perhaps, to say, that the
conception of the idea of an electric telegraph, was original with
me at that time, and I supposed that I was the first that had ever
associated the two words together, nor was it until my invention was
completed, and had been successfully operated through ten miles, that
I, for the first time, learned, that the idea of an electric telegraph
had been conceived by another. To me it was original, and its total
dissimilarity from all the inventions and even suggestions of others,
may be thus accounted for. I had not the remotest hint from others,
till my whole invention was in successful operation. I employed myself
in the wakeful hours of the night, as well as in the tedious hours of
the day, in devising the signs, adapting them to a single circuit of
wire, and in constructing machinery which should record the signs
upon paper, for I thought of no plan short of a mode of recording.”
On the second of September, 1837, the author, with several others,
witnessed the first exhibition of this electric telegraph, and soon
after became a partner with the inventor. Immediate steps were taken
for constructing an instrument for the purpose of exhibiting its powers
before the members of Congress. This was done at the Speedwell Iron
Works, Morristown, N.J. and exhibited in operation with a circuit of
two miles. A few days after, it was again exhibited at the University
of the City of New York, for several days, to a large number of invited
ladies and gentlemen. The circuit at this time was increased to ten
miles. Immediately after this exhibition the instruments and ten
miles of wire were taken to Washington, and continued in operation
for several months, in the room of the Committee on Commerce at the
capitol. Its history and progress, after this period, may be gathered
from the preceding documents, printed by order of Congress.
We make the following extract in relation to Schilling’s telegraph from
the Polytechnic Central Journal, Nos. 31, 32, 1838:
“Baron Schilling, of Caunstadt, a Russian Counsellor of State, likewise
occupied himself with telegraphs by electricity, (see Allgem Bauztg,
1837, No. 52, p. 440,) and had the merit of having presented a much
simpler contrivance, and of removing some of the difficulties of the
earlier plans. He reckoned many variations to the right, or left,
following in a certain order for a telegraphic sign, as, indeed, in
this manner, the needle was strongly varied, and only came to rest
gradually, after many repeated vibrations; he introduced a small rod
of platinum, with a scoop, which dipped into a vessel of quicksilver,
placed beneath the needle, and by the check given, changed the
vibration of the needle into sudden jerks. In order to apprise the
attendant of a telegraphic despatch, he loosed an alarm. How much of
this contrivance was Schilling’s own, or whether a portion of it was
not an imitation of Gauss and Weber, the author cannot decide, but that
Schilling had already experimented, probably with a more imperfect
apparatus, before the Emperor Alexander, and still later before Emperor
Nicholas, is affirmed by the documents quoted.”
From the report of the “Academy of Industry,” Paris, February, 1839, we
make the following extract, in relation to the same subject:
“At the end of the year, 1832, and in the beginning of 1833, M.
Le Baron de Schilling constructed, at St. Petersburg, an electric
telegraph, which consisted in a certain number of platinum wires,
insulated and united in a cord of silk, which put in action, by the aid
of a species of key, 36 magnetic needles, each of which were placed
vertically in the centre of a multiplier. M. de Schilling was the first
who adapted to this kind of apparatus, an ingenious mechanism, suitable
for sounding an alarm, which, when the needle turned at the beginning
of the correspondence, was set in play by the fall of a little ball of
lead, which the magnetic needle caused to fall. This telegraph of M. de
Schilling, was received with approbation by the Emperor, who desired it
established on a larger scale, but the death of the inventor postponed
the enterprise indefinitely.”
Dr. Steinheil in his article “upon telegraphic communication,”
published in the London Annals of Electricity, states, “that the
experiments instituted by Schilling, by the deflection of a single
needle, seems much better contrived, than the arrangement which Davy
has proposed, in which illuminated letters are shown by the removal of
screens placed in front of them.”
It would appear, that the French report is either incorrect, or that
M. de Schilling had two plans in contemplation. His plan as intimated
in the first and third extracts, is that of using a single needle in
the form of a galvanometer, by means of which he made his signals, for
instance, one deflection to the right might denote e; two i; three
b: one deflection to the left t; two s; three v.
His code of signals would then be devised in this manner:
| rl | A |
rrrl | K |
llr | U |
| rrr | B |
lrrr | L |
lll | V |
| rll | C |
lrl | M |
rlrl | W |
| rrl | D |
lr | N |
lrlr | X |
| r | E |
rlr | O |
rllr | Y |
| rrrr | F |
llrr | P |
rlrr | Z |
| llll | G |
lllr | Q |
rrlr | & |
| rlll | H |
lrr | R |
lrrl | go on |
| rr | I |
ll | S |
lrll | stop |
| rrll | J |
l | T |
llrl | finish |
| rlrlr | 1 |
lrlrl | 6 |
|
| rrlrr | 2 |
rrllr | 7 |
|
| rlllr | 3 |
rllrr | 8 |
|
| lrrrl | 4 |
llrll | 9 |
|
| lrrll | 5 |
llrrl | 0 |
|
If, however, his plan was that ascribed to him, by the Academy of
Industry, of using 36 needles and 72 wires, it was exceedingly
complicated and expensive, and was similar to that invented by Mr. Alexander,
with the exception that Schilling used twice the number of wires.
The deflection of the magnetic bar, by means of the multiplier, through
the agency of the galvanic fluid, excited by the magneto electric
machine, is the basis of their plan.
Fig. 51.
Figure 51 represents a side view of the apparatus, used at the
receiving station: a, a is a side view of the multiplier, composed
of 30,000 feet of wire, (almost 5½ miles,) upon a table, B: n, s is
the magnetic bar, weighing 30 pounds, from which rises a vertical stem,
o, upon which is a rod at right angles, supporting a mirror, H, on
one end, and at the other a metallic ball, I, as a counteracting weight
to that of the mirror. The magnetic bar is suspended by a small wire,
fastened to the vertical stem, and at the top is wound round the spiral
of the screw, i, which turns in the standards, h′ and h,
upon the platform, A, and which is secured to the ceiling. In the standards,
h′, there is cut a female screw, of the same gradation as that upon
which the wire is wound. By this means, the magnetic bar may be raised
or let down, by turning the screw, without taking the bar from its
central position in the multiplier: g is a screw for fastening the
spiral shaft, when properly adjusted. P and N are the two ends of the
wire of the multiplier. G is a stand for supporting the spy-glass, D,
and also the case, E, into which slides the scale, F. The mirror, H,
is at right angles with the magnetic bar, and presents its face to
the spy-glass, D, as also to the scale at E. It is so adjusted, that
the reflection of the scale at E, from the mirror, may be distinctly
seen by the spy-glass. If the magnetic bar turns either to the right
or left, the mirror must move with it, and if a person is observing
it through the spy-glass, the scale will appear to move at the same
time, thereby presenting to the eye of the observer another part of the
scale than that seen when the bar is not deflected. The figures on the
scale will show in what direction the bar has turned, and thus render
it distinct to the observer, the only apparent object of the mirror,
spy-glass and scale.
For the purpose of generating the galvanic fluid, they use the magneto
electric machine. Their plan, being unwieldy and difficult to operate,
is omitted, and in its stead, we introduce that form of it, invented
by Dr. Page, which has already been described in figures 45,
46 and 47.
There is also required for the purpose of making the desired
deflections of the magnetic bar, a commutator, or pole changer, such
as we have described in figures 48,
49 and 50.
Figure 51 represents that portion of the
apparatus at the receiving station. The magneto electric machine,
and the pole changer, properly connected, are the instruments of the
transmitting station. Two wires, or one wire and the ground, form the
circuit between these two stations. The machine is put in operation by
turning the crank, and the person sending the intelligence is stationed
at the commutator, and directs the current through the extended wires
to the multiplier of the receiving station, so as to deflect the bar
to the right or left, in any succession he may choose, or suspend its
action for any length of time.
“But in the apparatus for observation, the observer looks into the
spy-glass, and writes up the kind and results of the variations of the
magnetic needle. In order to have a control of the recorder, let there
be a good number of spy-glasses directed towards the same mirror, in
which observers may watch independently of each other. Suppose that
five variations of the magnetic needle signifies a letter. L denotes a
variation to the left, and R to the right. Then, might r r r r r denote
A; r r r r l denote B; r r r l r denote C; r r l r r denote D; and so
on. In the whole, we obtain, by the different arrangements of the five,
which are made with the two letters, R and L, 32 different telegraphic
signs, which may answer for letters and numbers, and of which we can
select those where the most changes are introduced between r and l,
as the most common letters, in order, in the best possible manner, to
notice the constant variations of the magnetic needle.”
The following would be the alphabetical signs, as arranged from the
above directions:
| A | rrrrr |
I or Y | llrll |
R | rrrll |
| B | rrrrl |
K | lrrrl |
S or Z | rrlrl |
| C | rrrlr |
L | rlrrr |
T | llrlr |
| D | rrlrr |
M | rrlll |
U | rlllr |
| E | rlrlr |
N | lllll |
V | lrrll |
| F | lrrrr |
O | lrlll |
W | llllr |
| G or J | lrlrr |
P | lrlrl |
| |
| H | rlrrl |
Q | llrrr |
| |
| Numerals. |
| 1 | rllll |
6 | rllrr |
| 2 | rrllr |
7 | lllrl |
| 3 | rlrll |
8 | llrrl |
| 4 | rllrl |
9 | lrrlr |
| 5 | lllrr |
0 | lrllr |
It will be seen, that, by representing the letters and numerals with
these variously combined deflections of the needle, words and sentences
may be transmitted. At the end of each letter there is a suspension of
the action of the bar for a short time, and at the end of a word, a
still longer pause. This plan of an electric telegraph was tried for
a distance of one mile and a quarter, in Göttingen. Of its further
success, we are not informed.
“Messrs. Taquin and Ettieyhausen made experiments with a telegraphic
line over two streets in Vienna, 1836. The wires passed through the air
and under the ground of the Botanic garden.”
No other account appears to have been given of their experiments than
that quoted above.
Soon after my connection with Professor Morse as copartner, and at the
time I was constructing an instrument for exhibiting the advantages of
his telegraph to a committee of Congress, it occurred to me, that a
plan might be devised, by means of which the letters of the alphabet
could be employed in recording telegraphic messages. I immediately gave
it my attention, and produced the following plan:
Figure 52 represents a front and side view of the instrument.
Figure 55 is a top view.
Figure 56 is a back view.
The same parts are represented by the same letters in the three views.
In figure 52, Q, Q is the platform upon which the whole
instrument is placed. M and M are wooden blocks supporting parts of the instrument,
K is the helix of the soft iron bar, H, passing through its centre, and
there is another coil and bar directly behind this; the two making the
electro magnet. G is its armature, fastened to the lever, F, F, which
has its axis at I, (seen in figure 55, at X, X.) R is a
brass standard for supporting the lever, F, upon its axis, by means of two pivot
screws: a and a are two screws passing vertically, through the
standard, R, for limiting the motion of the lever, F, F. J is a spiral
spring, at its upper end, fastened to the lever, F, and at its lower
end passes through the screw, L, by which it is adjusted, so as to
withdraw the armature from the magnet, after it has ceased to attract,
and for other purposes, hereafter to be explained. N and O is a brass
frame, containing the type wheel, B′, and the pulley, E and U. P and
P represent the edge of a narrow strip of paper, passing between the
type wheel and pulley, E. D is the printer, which, at the bottom, forms
a joint with the end of the lever F and r. B represents twenty-four
metallic pins, or springs, projecting at right angles from the side of
the type wheel; each pin corresponding in its distance from the centre
of the type wheel, to its respective hole, represented by dots upon,
the index, C; so that if the pin is put in any one of the holes, the
type wheel, in its revolution, will bring its corresponding pin in
contact with it.
Fig. 52.
There are 24 holes corresponding to the following letters of the
alphabet. A, B, C, D, E, F, G, H, I, K, L, M, N, O, P, Q, R, S, T,
U, V, W, X, and the types are lettered accordingly. The cog wheels,
T and S, are a part of the train of the clock. The lever, F, F, has
two motions, one up and another down, and both are employed by an
attachment at the end of the lever, r, and in the following manner:
figures 53 and 54 represent a front and
end view of the roller, E, and printer, D, (figure 52,)
enlarged. D is the printer, figure 53, of the
form shown by D, (figure 54.) E is the roller over which
the paper, P, is carried. A is the front of the type having ears, h, h, projecting
from each side. Through the sides of the printer, D, D, a rod, U,
passes, in order to give more firmness to the frame. The rod projects
a little on each side of the frame at J, J. These projections slide in
a long groove in the frames, N and O, figure 52, by which
the printer is kept in its position, and allowed freely to move up and down. It
will be observed that the upper parts of the frame, D, D, extends over
the top of the roller, E, and nearly touch each other, but are so far
separated, as to let the type, A, of the type wheel, in its revolution,
freely pass between them: d′, d′, are the sides of the joint, which
are connected with the lever, F, fig. 52. From the
construction of this part, it will appear that if the printer, D, is brought down
by the action of the magnet upon the lever, the two projections, k, k, will
come in contact with the ears, h, h, and bring the type in contact
with the paper upon the roller, E, and produce an impression. In figure 54
is shown a ratchet wheel, i, on the end of the roller, E, a catch,
e, and spring, c′, adapted to the ratchet. Upon the release of the
lever, F, fig. 52, the spring, J, will carry down the lever
on that side of its axis, and up at r, which will cause the roller, E, to
turn, and consequently the paper, P, to advance so much by the action
of the catch, e, upon the ratchet wheel, as will be sufficient for
printing the next letter.
Fig. 53. Fig. 54.
Figure 55 represents a top view of the machine. S is the
barrel upon which is wound a cord, sustaining a weight which drives the clock train,
and upon the same shaft with it is a cog wheel driving the pinion,
m, on the shaft, T; and on the same shaft, T, is another cog wheel,
driving the pinion, n, of the type wheel shaft, I′. K and K, are the
helices of the large magnet, of which H and H are the soft iron arms.
M, M, M, M, are the blocks which support the instrument. F and F is
the lever, a and a its adjusting screws; x′ and x′ its axis;
k and k are the two upper coils of the two electro magnets at the
back part of the instrument for purposes hereafter to be described;
x is the wire soldered to the plate buried in the ground; p is the
wire proceeding to the battery; c is the connecting wire of the two
electro magnets, k and k; w is the support of the pendulum; v is
the escapement wheel; A is the type wheel; D and D is the printer, and
B the roller over which the paper, P, is carried.
Fig. 55.
Fig. 56.
Figure 56 represents a back view of the instrument; k,
k and k, k are the coils of two electro magnets, surrounding the soft iron
bars, d, d and d, d; b and b are the flat bars through which
d, d and d, d pass, and are fastened together by the screw nuts
c, c and c, c. The right hand electro magnet is fastened to the
blocks, M and M, by the support, f and f; from which proceeds a
bolt passing between the coils, k and k, and the block, h, with
a thumb-nut upon it, by which the whole is permanently secured. In
the same manner the left hand magnet is secured to the block, M. R′
is the outside portion of the brass frame containing the clock work.
W is a standard fastened to R′, for supporting the pendulum, Y. X,
Y, and l are parts common to a chronometer for measuring the time,
viz. the escapement and pendulum. The escapement wheel has 24 teeth,
corresponding in number with the type on the wheel, and such is the
arrangement of the parts, that when the pendulum is upon the point of
return, either on the right or left hand, a type is directly over the
paper, and the armature, g, is near the face of one or the other of
the magnets; so that, if an impression is to be made with the type,
thus brought to the paper, the pendulum, Y, is ready to be held by the
magnet at the same time from making another swing until the type has
performed its office, which will be hereafter explained.
A shows the type as they are arranged on the wheel. The types are
square, and move freely in a groove, cut out of the brass type wheel.
At 1 and 2 are seen flat brass rings, which are screwed to the wheel,
and over the types, confining them to their proper places. Z is a
spiral spring, of which there is one to each type, by means of which
the type is brought back to its former position, after it is released
by the printer. Through each type there is a pin, against which the
inner end of the spiral spring rests. The outer end of the spring
rests against the circular plate. W represents the wire from the upper
helix, soldered to the metallic frame, R′. The two helices of the left
hand magnet are joined together, and from the bottom helix the wire
proceeds to the lower coil of the right hand magnet. These two helices
are likewise connected, and the wire leaves the upper coil at x. Thus
the wire is continuous from w to x. From x, the wire is
continued to a copper plate, buried in the earth. The frame, R′, being brass,
the arbor of the type wheel, and the wheel itself, and each being in
metallic contact, they answer as a continuous conductor with the wire,
w, for the galvanic fluid.
The index, c, figure 52, is insulated from the frame,
N, being made of ivory. There is inserted in the ivory, a metal plate, containing the
holes, to which is soldered a wire, q, connected with the back coil,
K. The two helices being connected, the wire of the front helix comes
off at p, and from thence is connected with one pole of the battery;
from the other pole, it is extended to the distant station, and is
there connected with a similar instrument. It will be observed, that
the circuit is continuous, except between the type wheel and the metal
plate in the ivory. When neither station is at work, the batteries of
both are thrown out, and their circuits, retaining in them the magnets
of both stations, are closed. For this purpose, there is an instrument
at each station, resembling in some respects the pole changer, figures
48, 49 and 50.
If one of the stations wish to transmit by reversing his
circuit instruments, the battery is instantly brought into the circuit.
Through the agency of the clock work and weight, and the pendulum,
both instruments are vibrating together, and their type wheels are
so adjusted, that when A type, of one station, is vertical, the A
type, of the other station, is also vertical. Now, suppose one station
wishes to transmit to the other, the word Boston, for example: he
first brings his battery in the circuit, then places a metallic pin in
the hole of his index, C, marked for the letter B. When the type wheel
shall have brought round the pin, corresponding to the type, B, on the
wheel, its pin will come in contact with the inserted pin of the index,
and instantly the circuit is established. The fluid, passing through
the coils of the magnets, on each side of the pendulum, will hold it,
and also passing through the coils, K, will bring down the lever, F, F,
and with it, the printer, D, which, as heretofore described, in figures
53 and 54, will bring the type, with considerable force,
against the paper. The instant the two pins have come in contact with the moving
pin, it is taken out and put in the hole, O, when the same operation is
performed, and in like manner for the remaining letters of the word.
The pin can be so arranged, as to be thrown out the instant a complete
contact is made.
The rapidity of this printing process would be as follows: Suppose the
pendulum makes two vibrations in a second; that is, it goes from right
to left in half a second, and returns in half a second. Since, then, a
single letter is brought to the vertical position, ready to be used
if needed, at the end of each vibration, it is clear, that two letters
are brought to the vertical position every second, or 120, every
minute. This is not, however, the actual rate of printing; for, in the
word Boston, the type wheel, after B is printed upon the paper, must
make so much of a revolution as will bring the letter O to the paper.
This will require 12 vibrations of the pendulum; S will require 4; T,
1; O, 18, and N, 22; equal to 57, to which add 6, the time required
to print each letter, will make it 63. This, divided by 2, gives 31½
seconds, the time necessary to print 6 letters. If we now take an
ordinary sentence, and estimate, in the same manner, the time required
to print it at the distant station, we shall be able to find what
number of letters it can print per minute.
“There will be a declaration of war in a few days, by this government,
against the United States. Orders have just been received to have all
the public archives removed to Jalapa, which is sixty miles in the
interior, for safe keeping.”
Here are 184 letters, and would require 2266 vibrations, to which add
184, the number of letters would give 2450 half seconds, equal to
1225 seconds, the time required for printing the message; or over 20
minutes; the rate being six and two-thirds seconds for each letter.
If, however, a vocabulary is used, with the words numbered, and
instead of using the 26 letters of the alphabet on the type wheel, we
substitute the 10 numerals, in their place, we reduce the time required
for a revolution of the wheel, and it is clear that this same message
may be transmitted in much less time.
The following numbers represent the words of the same message, in
the numbered vocabulary: 48687, 54717, 4165, 1, 12185, 34162, 54078,
25393, 1, 18952, 11934, 6177, 48766, 21950, 1106, 48652, 51779, 46532,
34475, 22991, 28536, 4321, 40254, 49085, 22991, 1391, 48652, 39087,
3845, 41278, 49085, 28536, 54536, 28668, 45008, 31634, 25393, 48652,
27326, 19865, 42813, 28592. Here are 42 numbers, and 196 figures. To
196 add 42, the spaces required, and we have 238 impressions to make,
to write the sentence thus represented. By calculation, we find there
is required, in order to bring each numeral and space in its proper
succession, to the vertical position, 1624 vibrations of the pendulum,
which, at the rate of two to the second, gives the time required to
transmit the message at 812 seconds, or nearly 13 minutes, being at the
rate of 18⅓ letters per minute.[29]
If, however, the vibrations of the pendulum are increased at the rate
of 4 in a second, then the time required for the transmission of the
message would be almost 7 minutes, and at the rate of 36⅔ letters per
minute.[30]
If it be increased to 6 vibrations per second, then the time would
be 4½ minutes, and at the rate of 55 impressions per minute.
The modes of using the English letter for recording telegraphic
messages are various, and they may be classed, as, First, Those which
are rapid in transmission; expensive in construction, and complicated
in machinery. Second, The less rapid in transmission; economical
in construction, and simple in its machinery. Third, The slow in
transmission; less expensive than the first class in construction; but
complicated in its machinery.
To the first class, belong those using 26 types; one for each of
the letters of the alphabet, and 13 extended wires, from station to
station, with more or less battery. These types are arranged in a row,
directly over the paper which receives the impression, and consequently
require a strip of paper some 4 or 5 inches broad. Each type is
furnished with an electro magnet and lever, answering as a hammer to
bring down the types upon the paper. As the types are arranged in a
straight line, they would present the following order:
| 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 |
| - | | | |
- | | - | - |
- | | | - |
| - | | P |
| R | | |
| | | |
| |
| - | | | |
- | | - | - |
I | | | - |
| N | | - |
| - | | T |
| | | |
| |
| - | | | |
- | | - | - |
I | | | - |
| N | | - |
| - | | - |
| | | |
| |
| - | | | |
- | | G | - |
| | | - |
| | | - |
| - | | T |
| | | |
| |
| - | | | |
E | | - | - |
| | | L |
| | | - |
| - | | |
| | | |
| |
| - | | | |
E | | G | - |
| | | |
| | | - |
| R | | |
| | | |
| |
| A | | | |
| | - | - |
| | | |
| | | P |
| | | |
| | | |
| |
| | | | |
| | | H |
| | | |
| | | |
| | | |
| | | |
| |
Here we have the style of this kind of printing. By spelling the
letters on the first line, then on the second, and so on, the words
“Printing Telegraph” can be made out. Those letters which follow each
other in the word, and also follow each other in the alphabet, are
placed upon the same line, but when a letter occurs preceding the last,
a new line must be taken, otherwise the word cannot be read. It will
appear, that in this mode, sometimes two or three, or four letters,
may be printed at one and the same instant, where they succeed each
other in alphabetical order. This plan is extremely rapid for one
instrument, but extremely slow for thirteen wires.
Supposing two such instruments are used upon a line of 40 miles, and
suppose the wire to cost per mile, fifty dollars. The expense for wire
alone would be $26,000. There are other expenses which we will omit
in this, as well as those plans which will be described hereafter.
Let it be assumed, in order to make equal comparison throughout, that
the number of successive motions of the type lever, in these various
plans about to be given, are 4 to a second. But as this instrument
may make, with two or more of its levers, two or more impressions per
minute, let it be 8 instead of 4 per second. It will then be capable
of transmitting 480 letters per minute. With all this, there are many
disadvantages, which will be developed as we proceed.
Under the same class, there is another plan, using the 26 types upon
the ends of as many levers, each lever employing the electro magnet,
and the line consisting of 13 wires. In this arrangement the types
are made to strike in any succession required by the message, at the
same point upon the paper, falling back and resuming their first
position, after having printed their letter, in order to allow the next
type to occupy the same point previously occupied by the other. The
printing of this plan will appear on paper as ordinary printing. Thus,
Printing Telegraph. If we suppose that 4 hammers,
carrying type, can strike the same point in a second, and each resume
their original position in succession, thus passing each other without
collision, it may print at the rate of 240 letters per minute.[31]
The instrument would be a complicated one and subject to derangement.
To the second class, belong all those which print in letters of an
hieroglyphical character. The first plan is that employing one wire
and one motion. Under this head, is that of Prof. Morse’s. He employs
but one wire and one electro magnet for printing, which has but one
motion. Suppose this to be capable of operating with the same speed as
the preceding, viz. four motions per second. The telegraphic alphabet
as adopted by Prof. Morse require for each letter the following
number of motions of the type or pen lever, as lines require time in
proportion to their length, they are so estimated: A 3, B 5, C 4, D 4,
E 1, F 4, G 5, H 4, I 2, J 6, K 5, L 5, M 4, N 3, O 3, P 5, Q 5, R 4,
S 3, T 2, U 4, V 5, W 5, X 5, Y 5, Z 5.
If we take the standard number of types for each letter
constituting it printer’s case, considering Z as 2, we shall have
A 85, B 16, C 30, D 44, E 120, F 25, G 17, H 64, I 80, J 4, K 8, L 40,
M 30, N 80, O 80, P 17, Q 5, R 62, S 80, T 90, U 34, V 12, W 20, X 4,
Y 20, Z 2. The whole number of letters are 1177. The number of motions
required to transmit them would be 3420, to which add, one motion for
the time required to space a single letter, and we have 4597 motions,
made in printing 1177 letters which will make the average number of
motions to each letter 3¹⁰⁶⁶⁄₁₁₇₇, nearly 4. Let it be 60 per
minute. Expense for one wire of 40 miles, $2000.
Second plan, is that where two wires are used, two magnets, two
type levers, and the telegraphic characters, such as are represented in
table 1, page 30. The first three letters require three motions each;
the next 16, require 2 each, and the last 7, require 3 each. Taking the
1177 letters, the motions required to transmit them in the characters
of this alphabet, would be, 2195 + 1177 for spaces and would equal
3372, which divided by 1177, would give the average number of motions
at 2¹⁰¹⁸⁄₁₁₇₇ for each letter, nearly three or 80 per minute.
Cost of wire $4000.
Third plan, is that using three wires, three magnets, three type
levers and the telegraphic characters represented in table second, page
30. The seven first would require one motion each, and the remainder
two each. Taking 1177 letters, the motions required to transmit them,
would be 1917 + 1177 for spaces, and would equal 3094 motions, which,
divided by 1177, would give the average number of motions 2⁷⁴⁰⁄₁₁₇₇
for each letter, nearly 2⅔, or 85 letters per minute. Cost of wire $6000.
Fourth plan consists in using four wires, four electro magnets, four
type levers, and the telegraphic characters of the third table. The
first sixteen letters require the time of but one motion each; the
remainder, two each. Using 1177 letters, the motions required to
transmit them would be 1506 + 1177 for spaces, and would equal 2683,
which divided by 1177, would give the average number of motions
2³²⁹⁄₁₁₇₇ for each letter, nearly 2⅓, or 103 letters per
minute. Cost of wire $8000.
Fifth plan, is that of using five wires, five electro magnets,
five type levers, and the telegraphic characters of the 4th table.
The characters would require one motion each, equal to 1177 + 1177
for spaces, and would equal 2354, which, divided by 1177, would give
the average number of motions, 2 for each letter, or 120 letters per
minute. Cost of wire $10,000.
We now come to the third class, in which 26 types are used, arranged
upon the periphery of a wheel, in alphabetical order, and require to be
brought to one certain point, where the paper is ready to receive the
impression of the type, by another arrangement, distinct from the type
wheel and its machinery. Of this plan, is that which has been already
described in figures 52, 55
and 56. The estimate is there carried out,
at 4 motions per second, gives 36⅔ letters per minute. Cost of wire
$2000.
The following table will show the comparative
value of these various methods:
| |
Letters per
minute. |
Cost. |
Number of
wires. |
On Morse’s
plan. |
No. |
| 1st Class. |
 |
1st | plan, |
480 | $26,000 |
13 | 780 |
1 |
| 2d | “ |
240 | 26,000 |
13 | 780 |
2 |
| 2d Class. |
 |
1st | plan, |
60 | 2,000 |
1 | 60 |
3 |
| 2d | “ |
80 | 4,000 |
2 | 120 |
4 |
| 3d | “ |
85 | 6,000 |
3 | 180 |
5 |
| 4th | “ |
103 | 8,000 |
4 | 240 |
6 |
| 5th | “ |
120 | 10,000 |
5 | 300 |
7 |
| 3d Class. |
|
1st | plan, |
37 | 2,000 |
1 | 60 |
8 |
We find by comparison that Morse’s plan,
No. 3, of using a single wire, with a single instrument, produces 60
characters per minute; while No. 1, with 13 wires, and one instrument,
produces 480 characters per minute. Let, however, the 13 wires be
multiplied by 60, (the number of characters which a single instrument
of the plan, No. 3, can transmit,) the number of characters which 13
wires, with 13 instruments would then produce, are 780 or 300 more than
the single instrument, with 13 wires. The same comparisons may
be made with the other plans, and it will be found that no advantage can
be gained by their adoption.
All electro magnetic telegraphs require as their basis, the adoption of
the electro magnet, where recording the intelligence is an object,
and it would seem, must be applied in a manner equivalent to that mode
adopted by Prof. Morse; that is, the application of the armature to a
lever, and its single movement produced by closing and breaking the
circuit. It is, therefore, safe to assume, that whatever improvement in
one plan may be made to increase the rapidity of the movements of those
parts of the telegraph which belong to the electro magnet, are equally
applicable to any other plan, provided too much complication, already
existing, does not counteract and defeat the improvement.
Some plans, however, use an extra agent besides the electro magnet,
which is employed for measuring the time of the revolution of the
type wheel, and the electro magnet is only called in, occasionally,
to make the impression. In such plans the rapidity of communication
demands the combined action, alternately, of both magnets. This, of
course, increases the complication, and must certainly be considered
a departure from other more simple arrangements. Whatever will reduce
the inertia of mechanical movements and bring them to act with an
approximate velocity, at least of the fluid itself, will increase the
rapidity of transmission. The more the instrument is encumbered with
the sluggish movements of material bodies, the less rapid, inevitably,
must be its operation, even where several co-operating agents are
assisting, in their respective spheres, to increase the rapidity of
the motion. Such is the case with the several kinds of letter printing
telegraphs: very weighty bodies, comparatively speaking, are set in
motion, stopped, again set in motion, and along with this irregular
motion, other parts perform their functions. There must be a courtesy
observed among themselves, or matters do not move on as harmoniously as
could be desired. This is not always the case, especially where time is
the great question at issue.
All printing telegraphs which use type, arranged upon the periphery of
a wheel, must have, of necessity, these several movements, viz. the
irregular revolution of the type wheel, stopping and starting at every
division or letter; the movement of the machinery, called the printer;
the irregular movement of the paper, at intervals, to accommodate
itself to the letter to be printed; the movement of the inking
apparatus, or what is not an improvement in cleanliness, paper of the
character used by the manifold letter writer. So many moving parts, are
so many impeding causes to increased rapidity, and are, to all intents
and purposes, a complication.
The requirements of a perfect instrument are: economy of construction,
simplicity of arrangement, and mechanical movements, and rapidity of
transmission. To use one wire is to reduce it to the lowest, possible
economy. If there is but one movement, and that has all the advantages
which accuracy of construction, simplicity of arrangement and
lightness, can bestow upon it, we might justly infer that it appeared
reduced to its simplest form.
The instrument employed by Professor Morse has but a single movement,
and that motion of a vibratory character; is light and susceptible of
the most delicate structure, by which rapidity is insured; the paper
is continuous in its movement, and requires no aid from the magnet to
carry it.
The only object that can be obtained by using the English letters,
instead of the telegraphic letters, is, that the one is in common use,
the other is not. The one is as easily read as the other, the advantage
then is fanciful and is only to be indulged in at the expense of time,
and complication of machinery, increasing the expense, and producing
their inevitable accompaniments, liability of derangement, care of
attendance, and loss of time.
The following description is taken from a pamphlet, published by T.
S. Hodson, 15 Cross street, Hallon Garden, London, 1839, for the
proprietors. It is unnecessary to copy the legal and technical wordy
mass of the specification, embracing fifty-nine pages of closely
printed matter of octavo size. A full description will be given,
with the accompanying figures, so as to enable the reader fully to
comprehend Mr. Wheatstone’s plan.
His arrangement requires the service of five galvanometers, in every
respect similarly constructed as that described by the figures 27,
28 and 29.
Figure 57 is a representation of his dial, which is
also a covering to the case containing, in the interior, the five
galvanometers and their wires, (shown at the opening in the dial
board,) and numbered, 1, 1; 2, 2; 3, 3; 4, 4, and 5, 5. The coils
of the multipliers are secured with their needles to the case,
having each exterior needle projecting beyond the dial, so as to be
exposed to view. Of the wires from the coils, five are represented
as passing out of the side of the case, on the left hand, and are
numbered 1, 2, 3, 4 and 5. The other five wires pass out on the
right hand, and are numbered in the same manner. The wires of the
same number as the galvanometer, are those which belong to it,
and are continuous. Thus the wire 1, on the left hand, proceeds
to the first coil of galvanometer 1, then to the second coil, and
then coming off, passes out of the case, and is numbered 1, on
the right hand. So of the other wires, thus numbered. The dial
has permanently marked upon it, at proper distances and angles,
twenty of the letters of the alphabet, viz. A, B, D, E, F, G, H,
I, K, L, M, N, O, P, R, S, T, V, W, Y. On the margin of the lower
half of the dial are marked the numerals, 1, 2, 3, 4, 5, 6, 7,
8, 9 and 0. The letters C, J, Q, U, X, Z, are not represented on
the dial, unless some six of those already there are made to sustain
two characters each, of which the specification is silent. Each needle
has two motions; one to the right, and the other to the left. For the
designation of any of the letters, the deflection of two needles are
required, but for the numerals, one needle only. The letter intended
to be noted by the observer, is designated, in the operation of the
telegraph, by the joint deflection of two needles, pointing by their
convergence to the letter. For example, the needles, 1 and 4, cut each
other, by the lines of their joint deflection, at the letter V, on the
dial, which is the letter intended to be observed at the receiving
station. In the same manner any other letter upon the dial may be
selected for observation. Suppose the first needle to be vertical, as
the needles 2, 3 and 5, then needle 4 being only deflected, points to
the numeral 4, as the number designed.
Fig. 57.
We will now proceed to describe the arrangement of the springs and
buttons upon the platform, C, C, figure 58, (representing a top view,)
by the operation of which, any two needles may be deflected to
designate a letter, or one needle to designate a numeral.
Fig. 58.
The numbers 6, 1, 2, 3, 4 and 5, represent keys of thin brass, and
elastic, and are each fastened to a wooden support, D, D, by means
of two screws. These keys are continued under and project beyond,
the brass bar, L and L, which is supported by two standards, R
and R. Whenever these keys are not pressed upon, they are each in
metallic contact with the bar, R and R. The numbers 7, 8, 9,
10, &c. represent ivory buttons with a metallic stem beneath them,
passing through a hole in the spring, or key, and on the lower side
of the spring the stem is enlarged, so as to form a kind of hammer,
designed to make a metallic contact with the two brass bars, beneath
the springs, and represented as supported by the standards, N and N
and P and P. Each of the buttons have a small wire spiral spring, to
which they are fastened, and the small spring is itself fastened to the
larger spring. O represents the galvanic battery, with its poles in
connection with the two metallic bars, N and P.
Figure 59 represents a side view of the key arrangement.
F is the platform. E the wooden support of the six keys. H is the larger spring,
or key, secured to the support by screws, h. The spring is observed
to project beyond the metallic cross bar, L, after passing beneath it.
R is the support of the cross bar, L. N and O are two of the ivory
buttons, upon their spiral springs, a and c. Below the button, O,
is a shoulder, formed at i, upon the stem which passes through the
spring, H, and another shoulder is formed by the hammer, u, below the
spring. It will be observed, that two buttons of the same key are never
used at the same time. If the button, O, is to be pressed down, the
weaker spring, c, will permit it to descend until the upper shoulder
comes in contact with the larger spring, H, when more pressure is
applied, and that spring is brought down, breaking its contact with
the metallic cross bar, L, until the hammer, u, comes in contact
with the metallic plate, n, upon the support, K, and as the plate,
n, is connected with N pole of the battery, the connection is formed
with it. It will, however, be noticed, that the button, N, not being
pressed upon, will not, (though it descends with the larger spring,)
be brought in contact with the other plate upon the support, J, and
connected with the positive pole of the battery. To the end of each spring,
a wire, S, is soldered, the purpose of which will be shown hereafter.
Fig. 59.
Fig. 60.
Figure 60 represents an end view of the key arrangement;
a, b, c, d, e, f, are the buttons, M and M
the metallic cross bar, beneath which are seen the ends of the six larger springs,
6, 1, 2, 3, 4 and 5. R and R are the supports of the bar, M and M. G
is the platform. W is the support of the metallic plates, with which
the hammers of the little keys, or buttons, come in contact. S the wire
leading to the battery.
Having shown the several parts of Mr. Wheatstone’s plan, we will
proceed to describe the arrangement of two termini, as prepared for
transmitting intelligence. Figure 61 represents the arrangement
of one station, which we may suppose to be Paddington.
Figure 62 represents the plan of the other station, which we will
suppose to be Slough. The distance between these two places
is eighteen miles.
In figure 61, it will be seen, that a wire is soldered
to the end of each of the springs 6, 1, 2, 3, 4 and 5, and are respectively connected
with the five wires of the dial, and the common communicating wire,
number 6, which does not pass through the dial, nor is connected with
any of the galvanometers. On the right hand side of the dial, the wires
are extended until they are shown as broken. From this point to the
opposite one, figure 62, where the wires appear also as
interrupted, we may suppose 18 miles to intervene. The wires here proceed to the
dial of the Slough station, making their proper connections with their
respective galvanometers, and from thence are continued and soldered
to their springs of the key arrangement, with the exception of wire,
number 6, which passes direct to the key, 6, without going through the
dial case. In both figures, is represented the battery, O, consisting
of six cups. The wire from one pole of the battery is connected with
the N metallic plate, the other wire with the P metallic plate. While
none of the buttons are pressed down, the battery is not in action,
and it will also be observed that the circuits are all complete.
The action of the keys, then, is this, by a single operation to break the
circuit formed with the cross bar, L, L, and, at the same time, bring
into the circuit, the battery, O.
The following numbers, representing the buttons, are those necessary to
be pressed down, in order to signal the letters and numerals on the dial:
| Letters. |
| For | A, |
buttons | 10 |
and | 17. |
For | M, |
buttons | 9 |
and | 12. |
| “ | B, |
“ | 10 |
“ | 15. |
“ | N, |
“ | 11 |
“ | 14. |
| “ | D, |
“ | 12 |
“ | 17. |
“ | O, |
“ | 13 |
“ | 16. |
| “ | E, |
“ | 10 |
“ | 13. |
“ | P, |
“ | 15 |
“ | 18. |
| “ | F, |
“ | 12 |
“ | 15. |
“ | R, |
“ | 9 |
“ | 14. |
| “ | G, |
“ | 14 |
“ | 17. |
“ | S, |
“ | 11 |
“ | 16. |
| “ | H, |
“ | 10 |
“ | 11. |
“ | T, |
“ | 13 |
“ | 18. |
| “ | I, |
“ | 12 |
“ | 13. |
“ | V, |
“ | 9 |
“ | 16. |
| “ | K, |
“ | 14 |
“ | 15. |
“ | W, |
“ | 11 |
“ | 18. |
| “ | L, |
“ | 16 |
“ | 17. |
“ | Y, |
“ | 9 |
“ | 18. |
Numerals. |
| For | 1, |
buttons | 7 |
and | 10. |
For | 6, |
buttons | 8 |
and | 9. |
| “ | 2, |
“ | 7 |
“ | 12. |
“ | 7, |
“ | 8 |
“ | 11. |
| “ | 3, |
“ | 7 |
“ | 14. |
“ | 8, |
“ | 8 |
“ | 13. |
| “ | 4, |
“ | 7 |
“ | 16. |
“ | 9, |
“ | 8 |
“ | 15. |
| “ | 5, |
“ | 7 |
“ | 18. |
“ | 0, |
“ | 8 |
“ | 17. |
Fig. 61.
PADDINGTON.
Fig. 62.
SLOUGH.
The direction of the current, when the letter V is to be signalled, is
this: pressing down the buttons, 9 and 16, at the Paddington station,
the fluid leaves the battery, O, along the wire to the cross bar, P;
then to the hammer of the button, 16; then to the spring, 4; then along
wire, 4, to the galvanometer, 4, and through it, deflecting the lower
half of the needle to the left; then along the extended wire, 4, to the
dial, and galvanometer, 4, of the Slough station, deflecting the lower
half of that needle to the left; then to wire, 4, leaving the dial, to
key, 4; then to the cross bar, L and L; and along the cross bar to key,
1; then to wire, 1; then to galvanometer, 1; and through it, deflecting
the lower half of the needle to the right; thence it proceeds along the
extended wire, 1, to the Paddington station; entering the dial to the
galvanometer, 1, deflecting the lower half of the needle to the right;
then along wire, 1, to the key, 1; then to button, 9; then to the cross
bar, N, beneath; and then to the negative pole of the battery, O. It
will be observed, that the needles of both stations, thus deflected,
point to the same letter, V. In Mr. Wheatstone’s arrangement, but one
person can transmit at the same time, although he uses six extended
wires. One must wait while the other is transmitting.
If a numeral is to be signalled, it is obvious, that but one
galvanometer is needed. We will, therefore, suppose that the needle, 1,
is vertical.
Let the buttons, 7 and 16, be pressed down, at the Paddington station.
The current then leaves the positive pole of the battery, O, to the
cross bar, P; then to the key, 4; then along wire, 4, to galvanometer,
4, deflecting the lower half of the needle to the left; from thence to
the Slough station to galvanometer, 4, deflecting the lower half of the
needle to the left; then to wire, 4; then to key, 4; then to the cross
bar, L and L, and along it to key, 6; then to wire, 6, and along the
extended wire to the Paddington station, to key, 6; then to the cross
bar beneath the button, 7; then to the negative pole of the battery, O.
The needles, 4 and 4, of both stations, are simultaneously deflected,
so as to point to the figure, 4, on the margin of the dial.
In this manner the circuits required for each letter and numeral may
be traced out. Now, suppose the message to be sent from the Paddington
station to the Slough station, is this, “We have met the
enemy and they are ours.” The operator at Paddington presses down
the buttons, 11 and 18, for signalizing upon the dial of the Slough
station, the letter W. The operator there, who is supposed to be
constantly on the watch, observes the two needles pointing at W. He
writes it down, or calls it out aloud, to another, who records it,
taking, according to a calculation given in a recent account, two
seconds at least for each signal. Then the buttons, 10 and 13, are
pressed down, and the needles are observed to point at E; and so for
the remaining letters of the sentence, U excepted, which has no letter
on the dial.
The peculiarity of Mr. Wheatstone’s plan, is, the employment of six
wires for one independent line of communication. The use of five
galvanometers, with their needles, by the deflection of which, 30
letters and numerals are pointed out. The messages are not recorded by
the instrument itself, but it is necessary that a person be constantly
observing the successive movements of the needles, and note them down
as they point to the signal. This plan was invented in 1837, and as
Prof. Wheatstone took out letters-patent in the United States, in 1840,
for this arrangement, it is a fair inference, that at that time, this
was his simplest and most perfect method.
Description of the magneto electrical telegraph, erected between Munich
and Bogenhausen, in 1837, by Dr. Steinheil,[32]
Professor of Mathematics and Natural Philosophy at the University of
Munich, taken from the Annals of Electricity, Magnetism and Chemistry,
conducted by William Sturgeon, London, April, 1839.
Fig. 63.
A, A represents a vertical section, through the centre of the coil of
copper wire. C is the interior brass frame, round which the wire is
wound. B and B are the sides of the frame; I, I, I, I are four brass
tubes, soldered to the interior brass frame, and passing through the
centre of the coil to its exterior, with a screw cut in the end of
each; D and D are two permanent magnets movable on their axis, a and
b. These spindles, a and b, on each side of the magnets, pass up
the hollow of the tubes, and having their ends pointed, enter the
centre cavity of the four thumb screws, J, J, J, J, by which they are
supported, and delicately adjusted, so as to move easily and freely. L
and L are the ends of the wire leaving the coil. H and K are two ink
holders, attached to the magnets, which will be explained hereafter.
Fig. 64.
Figure 64 represents a horizontal section of the coil,
and magnets D′ and D′, as above described, together with the other arrangements
of the instrument for receiving intelligence. The magnetic bars are
so situated in the frame of the multiplier, that the north pole, N′,
of the one, is presented to the south pole, S′, of the other. To the
ends which are thus presented to each other, but which, owing to the
influence they mutually exert, cannot well be brought nearer, there are
screwed on two slight brass arms, supporting little cups, H′ and K′.
These little cups, which are meant to be filled with printing ink, are
provided with extremely fine perforated beaks, that are rounded off in
front. When printing ink is put into them, it insinuates itself into
the tube of their beaks, owing to capillary attraction; and without
running out, forms at their apertures, a projection of a semiglobular
shape. These little cups are seen at H′ and K′, and in figure 63
at H and K. The horizontal section shows, also, the position of the magnets
in the instrument, with the beaks of the pens near the continuous band,
or ribbon of paper, E, which is brought in front of the pens vertically
from below, over a small roller, F. The paper is supplied from a large
roll on a wooden cylinder, upon which is a cog wheel, and connected
with a train of wheels and a vane, to regulate the rate of supply. The
paper is drawn along before the pen by being wound upon a cylinder,
T, concealed by the paper, and on the same shaft with the barrel, M,
upon which is wound a cord supporting a weight, N, below. The shaft is
supported in the standards, o and o, which are fastened to
a plate of brass, P and P, also secured to the platform of the instrument.
The barrel revolves in the direction of the arrow upon it.
When the electricity is transmitted through the coil of the indicator,
both magnetic bars, D′ and D′, make an effort to turn in a similar
direction upon their vertical axis, a and b. One of the cups
of ink, therefore, advances towards the paper, while the other recedes.
To limit this action, two plates, V and V′, are fastened at the opposite
ends of the free space, allowed for the play of the bars, and against
which the other ends of the bars press. Only the end of one bar can,
therefore, start out from within the multiplier at a time, the other
being retained in its place. In order to bring the magnetic bars back
to their original position, as soon as the deflection is completed,
recourse is had to two small movable magnets, a portion of which is
seen at N and S, whose distance and position are to be varied till
they produce the desired effect. This position must be determined by
experiment, inasmuch as it depends upon the intensity of the current
called into play.
Having described the instrument, its operation is as follows: At the
transmitting station is the pole changer, such as we have described
in figures 48, 49
and 50, and the magneto electric machine such as
is described in figures 45, 46,
and 47, and are properly connected, and
in the circuit with the instrument of the receiving station, such
as we have just described. For one single circuit, one wire extends
from the transmitting to the receiving station, the return half of the
circuit is the earth. Thus the current passes from the generator along
the extended wire to the receiving station, and to the copper plate,
then returns through the ground to the copper plate of the transmitting
station, to the pole changer and the magneto electric machine. Thus the
circuit is complete.
It is clear, from what has preceded, that when the pole changer is
thrown to the left side, (the machine being in operation,) the fluid
is made to pass in the direction of the arrows, shown at P and N. Then
the N′ pole of the left hand magnet advances with its pen, K′, to the
paper, E, and a dot is made, and the S′ pole of the right hand magnet
recedes with its pen, H, from the paper, until the other end of the
magnet strikes the stop, V′. Now, if the letter to be formed, requires
two dots in succession from the same pen, the circuit is broken, and
the fixed magnets, N and S, bring back the deflecting magnets, D′ and
D′, to their former position, when the pole changer is again thrown to
the left, and the magnets are deflected in the same manner as at first.
Thus two dots are marked upon the paper, on the right hand line. But,
now, let the pole changer be thrown to the right hand side, and the
current is reversed. The N′ pole of the left hand magnet, with its pen,
K, recedes from the paper until it strikes the stop, V, and the S pole
of the right hand magnet, with its pen, H′, advances to the paper and
makes its dot upon it on the left hand line. The pole changer is then
instantly brought to the middle position, and the magnets resume their
natural place, by the assistance of the stationary magnets, N and S.
The sign which has been marked upon the paper during this operation is
· ·
·, and represents 9.
The following represents Mr. Steinheil’s telegraphic alphabet:
| |
| · | ·· |
· | |
·· | ·· |
···· | |
· · | · |
· | · |
| · · | · · |
| · |
· | · |
| ···· |
· · | |
·· | ·· |
| A | B |
D | E |
F | G |
H | CH |
SCH | I |
K | L |
| | ··· |
·· | |
· · | |
·· | · |
· · | · · |
·· | |
| | |
| ··· |
·· | ·· |
·· | · |
· | · · |
·· | |
| | M |
N | O |
P | R |
S | T |
V | W |
Z | |
| | ··· |
· ·· | ·· · |
··· | · |
· | · |
· | ·· |
| |
| | · |
· | · |
· | ··· |
· ·· | ·· · |
··· | · |
··· | |
| | 1 |
2 | 3 |
4 | 5 |
6 | 7 |
8 | 9 |
0 | |
| |
“In 1837, M. Masson, Professor of Philosophy at Caen, made trial of
an electric telegraph, at the college of that city, for a distance of
about 600 metres. He employed, for developing the galvanic current,
an electro magnetic apparatus, similar, on the contrary, to that of
Mr. Pixii, and made it act on magnetic needles placed at two ends of
the circuit. Since that time, however, M. Masson has endeavoured to
simplify and gradually improve his apparatus.”[33]
The following extracts from the London Mechanic’s Magazine, vol. 28,
page 296 and 327, 1837, is all the description we are able to find in
relation to it:
“There is a case, which may serve as a desk to use in writing down the
intelligence conveyed; and in this, there is an aperture about sixteen
inches long, and three or four wide, facing the eyes, perfectly dark.
On this the signals appear as luminous letters, or combinations of
letters, with a neatness and rapidity almost magical. The field of
view is so confined, that the signals can be easily caught and copied
down without the necessity even of turning the head. Attention, in
the first instance, is called by three strokes on a little bell; the
termination of each word is indicated by a single stroke. There is
not the slightest difficulty in decyphering what is intended to be
communicated.”
Extract from page 327.
“In front of the oblong trough, or box, described by your
correspondent, a lamp is placed, and that side of the box next the
lamp is of ground glass, through which the light is transmitted for
the purpose of illuminating the letters. The oblong box is open at the
top, but a plate of glass is interposed between the letters and the
spectator, through which the latter reads off the letters as they are
successively exposed to his view. At the opposite side of the room,
a small key board is placed, (similar to that of a piano forte, but
smaller,) furnished with twelve keys; eight of these have each three
letters of the alphabet on their upper surfaces, marked A, B, C; D, E,
F; and so on. By depressing these keys in various ways, the signals or
letters are produced at the opposite desk, as previously described, how
this is affected is not described by the inventor, as he intimated
that the construction of certain parts of the apparatus must remain
secret. By the side of the key board, there is placed
a small galvanic battery, from which proceeds the wire, 25 yards in length,
passing round the room. Along this wire the shock is passed, and
operates upon that part of the apparatus which discloses the letters
or signals. The shock is distributed as follows: The underside of the
signal keys are each furnished with a small projecting piece of wire,
which, on depressing the keys, is made to enter a small vessel, filled
with mercury, placed under the outer ends of the row of keys; a shock
is instantly communicated along the wire, and a letter, or signal, is
as instantly disclosed in the oblong box. By attentively looking at the
effect produced, it appeared as if a dark slide were withdrawn, thereby
disclosing the illuminated letter. A slight vibration of the (apparent)
slide, occasionally obscuring the letter, indicated a great delicacy
of action in this part of the contrivance, and although not distinctly
pointed out by the inventor, is to be accounted for in the following
manner: when the two ends of the wire of the galvanic apparatus are
brought together, over a compass needle, the position of the needle is
immediately turned, at right angles, to its former position; and again,
if the needle is placed with the north point southward, and the ends
of the wire again brought over it, the needle is again forced round to
a position at right angles to its original one. Thus, it would appear,
that the slide or cover over the letters, is poised similarly to the
common needle, and that by the depression of the keys, a shock is
given in such a way as to cause a motion from right to left, and vice
versa, disclosing those letters, immediately, under the needle so
operated upon.”
“A model to illustrate the nature and powers of this machine was
exhibited on Wednesday evening at the Society of Arts in Edinburgh.
The model consists of a wooden chest, about five feet long, three
feet wide, three feet deep at the one end, and one foot at the other.
The width and depth in this model are those which would probably be
found suitable in a working machine, but it will be understood that
the length in the machine may be a hundred or a thousand miles, and
is limited to five feet in the model, merely for convenience. Thirty
copper wires extend from end to end of the chest, and are kept apart
from each other. At one end (which, for distinction’s sake, we shall
call the south end) they are fastened to a horizontal line of wooden
keys, precisely similar to those of a piano forte; at the other, or
north end, they terminate close to thirty small apertures, equally
distributed in six rows of five each, over a screen of three feet
square, which forms the end of the chest. Under these apertures on
the outside, are painted, in black paint, upon a white ground, the
twenty-six letters of the alphabet, with the necessary points, the
colon, semicolon, and full point, and an asterisk, to denote the
termination of a word. The letters occupy spaces about an inch square.
The wooden keys, at the other end, have also the letters of the
alphabet, painted on them in the usual order. The wires serve merely
for communication, and we shall now describe the apparatus by which
they work.
This consists, at the south end, of a pair of plates, zinc and copper,
forming a galvanic trough, placed under the keys; and at the north end,
of thirty steel magnets, about four inches long, placed close behind
the letters painted on the screen. The magnets move horizontally on
axes, and are poised within a flat ring of copper wire, formed of the
ends of the communicating wires. On their north ends they carry small
square bits of black paper, which project in front of the screen, and
serve as opercula, or covers, to conceal the letters. When any wire is
put in communication with the trough at the south end, the galvanic
influence is instantly transmitted to the north end; and in accordance
with the well known law, discovered by Oersted, the magnet at the end
of that wire instantly turns round to the right or left, bearing with
it the operculum of black paper, and unveiling a letter. When the
key, A, for instance, is pressed down with the finger at the south
end, the wire attached to it is immediately put in communication with
the trough; and at the same instant, letter A, at the north end is
unveiled, by the magnet turning to the right, and withdrawing the
operculum. When the finger is removed from the key, it springs back to
its place; the communication with the trough ceases; the magnet resumes
its position, and the letter is again covered. Thus by pressing down
with the finger, in succession, the keys corresponding to any word or
name, we have the letters forming that word, or name, exhibited at the
other end; the name Victoria, for instance,
which was the maiden effort of the telegraph on Wednesday evening.”
Fig. 65.
The above description is all that we have been able to obtain in
relation to this plan of an electric telegraph and here introduce,
figure 65, to illustrate it. The 30 needles are represented
on the screen, each carrying a shade, which conceals the letter when the
needle is vertical. The needle belonging to the letter F, is, however,
deflected, and the letter is exposed. The screen is supposed to be at
the receiving station. To the left hand of the screen, 30 wires, e,
e, are seen joined to one, a; the other 30 wires, d, d, are seen
below the screen. These wires may be supposed to extend many miles, and
to be joined with their corresponding wires, c, and also v, v, of
the transmitting station, where it will be observed, the wire, c,
connects with the battery at one pole, and from the other pole a wire
is continued and soldered to the metallic plate, o, o, which extend
under all the 30 keys, i, i. These keys are each insulated, at their
extremity, by being fastened to a wooden standard, L, L, to which a
wire is soldered. Now, suppose the key, F, is pressed down, (the sixth
key from the left,) the fluid then passes from the battery, B, through
the wire to o, the plate; then to the key in contact with it; then to
its wire, marked by the arrow; thence through the extended wire to its
corresponding wire at the receiving station, denoted by the arrow; then
through the coils of the multiplier, deflecting the needle, F; then
returns through its wire, at the left, to the common wire, a; then
through the extended wire to C, and the battery, of the transmitting
station. In this manner any letter upon the screen may be indicated.
“M. Amyot announced, in a letter addressed to the Academy of Sciences,
in April, 1838, that he also proposed to construct an electric
telegraph. It was to consist of a single current, which would move
a single needle, which needle would of itself write on paper, with
mathematical precision, the correspondence which might be transmitted
to the other extremity, by a simple wheel on which it should be
written by means of points, differently spaced, the same as they are
on the barrels of portable organs. In order to send any news then,
he required to write, by means of movable characters, which must be
constructed in a certain manner, and immediately it would be repeated
and transcribed at the place where he wished to address it, on paper,
which could be put into the hands of persons specially employed to
transmit despatches. But all that method of execution, which it seems
ought to move is clock work, not having been sufficiently described
by the author, the most vague uncertainty yet reigns as to the true
construction of that apparatus, which appears to us to have been for M.
Amyot, rather the occasion, than the end, of this communication; for
indeed he attempted to make the possibility admitted of establishing a
universal telegraphic language of his invention.”
The following description of Mr. Davy’s telegraph is taken from his
specification and drawings, published in the Repertory of Patent
Inventions. Although the specification has given the basis of his plan,
yet the description contained therein, and the drawings representing
his plan, are so obscure and deficient, that to have given it to
the public in that form, would have represented it as perfectly
impracticable. He has failed to state the number of signals which it
is capable of giving. He has committed great errors in the arrangement
of his wires for producing signals. He has introduced two keys, which
produce the same signals as two others in the same arrangement. He
has employed three extended wires for communicating from one station
to another station, and by his arrangement of them, could not have
obtained more than four signals. He has also very obscurely described
his escapement, by which his marking cylinder is made to advance one
division at a time for receiving the signals. This latter difficulty,
however, we have been enabled to clear up, by a description of it in
a work published by Mr. Bain. Notwithstanding the imperfections and
obscurities of his specification and drawings, we have endeavoured to
carry out his plan, and give it a practical shape, perhaps, as Mr. Davy
originally designed it.
As it is now described, there are 26 signals, or marks, indicating
letters. The employment of four wires instead of three, or if Mr. Davy
chooses to use for the common communicating wire the ground, which is
perfectly practicable, it will reduce the number to three, the number
he has specified. We have introduced one key more, and so arranged the
two superfluous keys as to make them available. With this preliminary,
we will proceed with the description.
Fig. 66.
Fig. 67.
Figure 66 represents a top view of the arrangement of
the wires, mercury cups, and batteries of the transmitting station. The close
parallel lines represent the wires, of which D, A, B and C are those
which proceed to the receiving station. 1′, 2′ and 3′ are the three
batteries, of which, P and N are their respective poles. The small
circles formed at the termination of the wires, and marked 7, 1, 10, 2,
20, &c. are mercury cups, in which the terminating wires are immersed.
The wires 1 and 20, and 2 and 10, &c. which cross each other, are not
in contact, but perfectly insulated. The wires shown in this figure,
are all secured permanently, with their mercury cups, to one common
base board. The letters H, J, K, M, O and U represent the places of the
six finger keys, used in transmitting signals. There is, also, another
key at 7, for uniting the wire, D and D. In this figure,
however, the keys themselves are omitted, in order to render more clear the
arrangement of wires under and around them. Another figure, 67,
is here introduced to illustrate the plan of one set of wires and their two
keys. In figure 67 is represented, in a top view, the two
wooden keys, A and B, and their axes, at E and F. G is the battery, of which, 9 is
the positive pole, and 10 the negative pole. The small circles, marked
1, 2, 3, 4, 5, 6, 7 and 8 represent the mercury cups. C and C′, and
also, D, are the extended wires. The keys, A and B, have each two
wires, passing at right angles through the wooden lever. The wires of
the key, A, are marked 1 and 2, and 5 and 6, and those of the key, B,
are marked 3 and 4, and 7 and 8. These wires, directly over the mercury
cups, are bent down a convenient length, so as to become immersed in
the cups, when the lever is depressed, and rise out of them, when the
lever is elevated. Now, if the key, A, is depressed, the cup, 1, is
brought in connection with cup 2; and 5 is connected with 6, by the
wires, supported by the lever, being immersed in the mercury; and the
key, B, not being depressed, there is no connection of the cup 3 with
4; or 7 with 8. At X and X, under the lever, are springs, which keep
the lever elevated; and, consequently, the wires out of the cups, when
the keys are not pressed down.
Fig. 68.
Figure 68 represents a side view of the lever, or key,
A, and its axis at E. R is the platform supporting the standard of the axis;
the stationary wires; the battery, G; and the mercury cups, a, a
and 10. X is the spiral spring, for the purpose of carrying back the
lever, after the finger is taken off and sustaining it in its elevated
position. Through the centre of the spiral, passes a rod, with a head
upon it at the top of the lever, to limit its upward motion. At its
lower end, the rod is secured in the platform, R. 4 and 8 are the two
wires supported by the lever, A, and are seen to project down directly
over the mercury cups, a and a, so that by depressing the key,
they both enter the cups and form a metallic connection. The key, B,
figure 67, has the same fixtures and is similarly
arranged as the key, A, represented above.
Fig. 69.
Figure 69 represents a top view of die arrangement
of multipliers at the receiving station. R′, R′ and R′; R, R, and R are
six magnetic needles, or bars, each of which move freely upon a vertical
axis passing through their centres. The lower point of their axes
is immersed in cups of mercury, in which also terminate the wires,
I, I, I and L, L, L. The wires, D″, A′, B′ and C′, are those coming
from the transmitting station. A′, B′ and C′, each enter the needle
arrangement, and first passing from left to right, over the magnetic
bars, R′, R′ and R′, in the direction of their length, then down and
under and round, making many turns, leave these three needles and
pass under the needles, R, R and R, and in like manner from right
to left round them, making a number of turns, then pass off and unite
together, in the wire, 9, which is a continuation of D″. This wire is
called the common communicating wire,[35]
and the wires, A′, B′ and C′ are called signal wires. At right
angles, there projects from each magnetic bar, a metallic tapered arm,
which rests against the studs, V, V, V, V, V, V, when the needle is
undisturbed. But when the needles are made to move in the direction,
to carry the arms to the left, they are brought in contact with the
metallic stops, S, S, S and T, T, T. To each of these stops, it will
be observed, a wire is soldered, and continued respectively from S, S,
S to ̈1, ̈3, ̈5, and from T, T, T to ̈2, ̈4, ̈6. It will
also be observed, that from each of the mercury cups below the magnetic
bars, the wires, I and L, and I and L, and I and L, proceed and unite
in pairs at, L, L, L; these three united wires are then continued, and
the whole are joined in one at 8. The wires, ̈1, ̈2, ̈3, ̈4,
̈5, ̈6, are continued, in a manner hereafter to be described,
and are connected with one pole of a battery. The wire, 8, is also
continued and connected with the other pole. So that if any one of the
needles should be made to move its arm to the left, thereby coming in
contact with its metallic stop, the circuit would be complete and the
current would pass along the wire, ̈1, for example, to the metallic
stop, then to the arm, and to the magnetic bar; then to the axis; then
to the mercury; then to the wire, I, and thence to the wire, 8. In the
same manner the current would pass if any other arm was brought against
its metallic stop. All the wires represented in this figure
are permanently secured in their places upon a common platform.
In order to understand the combined operation of the keys and needles,
figure 70 is here introduced. The right hand figure,
is the same as figure 69, and the left hand the
same as figure 66.
Fig. 70.
TransmittingPart of Receiving
Station.Station.
The wires, D″, A′, B′ and C′, are detached from their corresponding
wires of the transmitting station, and it may be imagined that many
miles of wire intervene and connect the two. In the left hand figure,
those mercury cups above and below, 1 and 10, are joined by two
wires passing through a moving lever, in the same manner as has been
described in figure 67. We will, therefore, call the
key, carrying these two connecting wires, H. In like manner the key for the
cups above and below the numbers, 2 and 20, is called J; for 3 and 30, is
K; for 4 and 40, is M; for 5 and 50 is O; for 6 and 60, is U. The key
which connects the two mercury cups on the right and left of number 7,
of the wire, D″, is called 7. There are 7 keys; two for each battery,
1′, 2′ and 3′, and each wire, A′, B′ and C′; and one for the common wire, D″.
It will now appear, that if the key, U and 7, are depressed, the cups
above and below, numbers 6 and 60; and the cups on each side of number
7, will be connected together so that the current leaving, P, or the
positive pole of the battery, 3′, goes to the lower cup, 50; then by
the stationary cross wire to upper cup, 6; then passes to lower cup,
6, by the wire supported by the lever, U, which is now pressed down,
and its ends immersed in the two cups; then along the wire, D, to the
left hand cup, 7; then to the right hand cup, 7, by the wire supported
by the lever, 7, and which is immersed in the two cups; then through
the extended wire to D″, of the receiving station; then through 9,
to the two multiplying coils of the wire, C′, deflecting the arm of
the needle, R, to the right, against the stop, V; and the arm of the
needle, R′, to the left against the metallic stop, S, as indicated by
the arrow at S; then along the extended wire, back to the lower cup,
60, of the transmitting station; then to upper cup, 60, through the
wire supported by the lever, U; then to N, the negative pole of the battery, 3′.
It will be observed of the two needles, R and R′, in the circuit of the
same wire, C′, that if R is deflected to the right against the stop,
V, then R′ will be deflected to the left against the metallic stop, S.
The current, to produce these deflections, being through the wire C′,
in the contrary direction to that indicated by the arrow of the wire,
C′. But if R is deflected to the left against the metallic stop, T,
then R′ will be deflected to the right against the stop, V. The current
to produce these deflections, will then be through the wire, C′, in
the direction of the arrow of that wire. The same effect is produced
upon the two other pairs of needles of the wires, A′ and also B′. These
contrary movements of the two needles, when a current is passing, are
produced by the coils being so wound, (see figure 69,)
that the wire passes round one needle in a contrary direction to what it
does round the other.
If, now, we depress the keys, O and 7, the cups above and below, 5 and
50, and on each side of number 7, will be connected. The fluid will
then pass from P or positive pole of the battery, 3′, to the lower cup,
50; then through the key wire to upper cup, 50; then along the extended
wire, C′ to the receiving station; then through the coils of the
multipliers, deflecting the arm of the needle, R, to the left against
the metallic stop, T; and the arm of the needle, R′, to the right
against the stop, V, as indicated by the arrow at V; then to wire,
9 and D″; then along the extended wire back to the transmitting
station, to the right hand cup, 7; then by the key wire to the left
hand cup, 7; then to wire, D; then to upper cup, 5; and through the key
wire to lower cup, 5; then by the cross wire to upper cup, 60, and then
to N, or negative pole of the battery.
We have now shown the route of the current, when the keys, U and 7; and
the keys, O and 7, were depressed. It will be observed, that when the
keys, U and 7 were used, the current through the wire, D″, was from
left to right; and when the keys, O and 7, were used, the current
was from right to left. Thus, by means of the six keys, the current
of each battery may be made to pass in either direction through the
common communicating wire, D″. By the keys, U, M, J, with 7, the
current is made to pass from left to right along the wire, D″.
By the keys, O, K, H, with 7, the current is made to pass from right
to left along the wire, D″. By these six keys, all those various
deflections of the six needles are produced, which are necessary
to close the circuit of such of the wires, ̈1, ̈2, ̈3, ̈4,
̈5, ̈6, with the wire, 8, as are required for marking the signals
desired, on an instrument now to be described.
Fig. 71.
Fig. 72.
Figure 71 represents a top view of that part of the instrument
at the receiving station, by which the signals are recorded. The seven wires
on the left of the figure are a continuation of those wires,
marked ̈1, ̈2, ̈3, ̈4, ̈5, ̈6, and 8, in figure 70. The first
six pass through a wooden support, b and b, and terminate upon the
edge of the platinum rings, a, a, a, a, a and a,
forming a metallic contact. The six platinum rings surround a wooden insulating
cylinder, t, which revolves upon axes in the standards, h and
i. The rings are broad where they come in contact with the wooden
roller, and are bevelled to an edge where they come in contact with
the six wires. Y represents a compound battery, with one pole of which,
wire 8, from the needle arrangement, figure 70, is connected,
and from the other pole the wire proceeds to the electro magnet, Z, Z; it then
passes on and is brought in connection with the metallic cylinder,
d, at the point, g. The cylinder, d, revolves upon axes, and
is supported in the standards, k and l. To the cylinder is attached
a barrel, n, upon which is wound a cord, supporting the weight,
e, by which the cylinder is made to revolve. C′, C′, represents a
prepared fabric, such as calico, (impregnated with hydriodate of potass
and muriate of lime,) and is placed between the platinum rings, a,
a, a, a, a, a, and the metallic cylinder, d; o is a cog wheel
upon the end of the axis of the cylinder, d, and is connected with
other machinery, omitted here, but shown in figure 72,
which is a side elevation of part of figure 71: o is the cog wheel,
(figure 72,) on the arbor of the cylinder,
d. B and B, are the two sides of the frame
containing the clock work, and is secured to the platform, R: d is
a part only of the metallic cylinder, upon which is seen a portion of
the prepared fabric, K. The cog wheel, o, drives the pinion, A, on
the shaft of the fly vane, G. M is an end view of the electro magnet,
(represented by Z, Z, in figure 71,) of which N and P
are the two ends of the wire composing the helix. D is its armature, constructed
so as to move upon an axis represented by two small circles. To the armature
are connected, and capable of moving with it, two arms, E and I, which
project, so as to come in contact with the pallet, a, of the fly, G.
F is a spiral spring, one end of which is fastened to the armature,
D, and the other passes through a vertical hole in the screw, S, in
the bar, T, by which the armature is held up in the position now seen,
when not attracted by the electro magnet. Now, if the wires, N and P,
connected with battery, Y, (figure 71,) have their
circuit closed, the current passing through the helix of the magnet, M, brings
down the armature, D, in the direction of the arrow, which raises the arm,
I, against which the pallet, a, of the fly vane, is resting, and
releases the fly. It then makes a half revolution and is again arrested
by the pallet against the lower arm, E, and the cylinder, d, with its
fabric, has advanced a half division. If the circuit is now broken, the
armature, D, is carried up by the spring, F, at the same time the arm,
E, releases the pallet, a, and the fly makes another half revolution,
and is again stopped by the arm, I. The cylinder has now made another
advance of half a division, which, together, makes a whole division the
fabric has advanced. The purposes for which this is designed will now
be described.
Fig. 73.
Figure 73 represents a top view of the whole apparatus
of the receiving station. The fabric, C′, C′, is marked in equal divisions
across it, and in six equal divisions, in the directions of its length,
thus marking it into squares. Each platinum ring, a, a, a, &c.
(when the instrument is not in operation,) is in contact with the fabric at
the middle of the squares across the fabric. It will be observed,
that the wires ̈1, ̈2, ̈3, ̈4, ̈5, ̈6 are in connection
with the battery, Y, and the circuit complete, except at the arms of
the needles. Suppose, for example, the arm of the needle, R′, of the
wire, C′, is brought up against the stop of the wire, ̈5, at S; the
circuit is then closed, and the current leaves the battery, and passes
to the electro magnet, (causing the cylinder and fabric to move half a
division,) then to the metallic cylinder, d; then through the fabric,
c′, c′, resting upon the cylinder, (where it is in contact with the
platinum ring, a, of the wire, ̈5,) then to the platinum ring; then
to wire ̈5; then to the metallic stop, S; then to the arm of the
needle, R′, along its axis to the mercury; then to the wire, I; then
to wire, 8, and to the other pole of the battery, Y. Thus a current is
passed through the prepared fabric, and a mark produced thereon, in the
middle of its square. If the circuit is now broken, the cylinder moves
another half division, which will bring the rings to the centre of the
squares, ready for the next signal.
But one battery, Y, is used for all the six circuits, formed with the
wire, 8; so that, when three of the circuits are closed at the same
instant, as will be shown hereafter, the current passes through the
three wires of their respective circuits, making each their appropriate
mark upon the fabric.
We now proceed to describe the manner of operating with the two
instruments, at their respective stations: and, first, we must here
designate each needle by its own peculiar mark of reference. Let the
two needles upon the wire, A′, be denoted by, A, S and A, T; those of
the wire, B′, by B, S and B, T; and those of the wire, C′, by C, S and
C, T. It will appear obvious, from the foregoing description, that
but one needle of each wire, A′, B′, C′, can be made to close its
circuit at the same instant. However, two needles, or three needles
of different wires, may close their circuits at the same instant,
but no higher number than three. The various combinations of one
mark, two marks, and three marks, upon the same row of six cross
divisions of the fabric, constitute the characters representing letters.
Fig. 74.
London.—Transmitting Station.
Figure 74 represents the transmitting station, which may
be supposed to be London, and figure 75, the receiving
station, which may be at Birmingham, with four wires extending from station to station, or
three only, if the ground be substituted for the wire, D, D″. The
wires, D, A, B and C, are supposed to be united with D″, A′, B′ and
C′, respectively. Now, if we depress the keys, in the following order,
we shall, for each key, have the following deflections of the two
needles, belonging to each key.
| No.1. |
| The keys, | H, 7, |
moves the arm, | A, S, |
to the | right, |
A, T, | to the |
left. |
| “ | J, 7, |
“ | A, S, |
“ | left, |
A, T, | “ |
right. |
| “ | K, 7, |
“ | B, S, |
“ | right, |
B, T, | “ |
left. |
| “ | M, 7, |
“ | B, S, |
“ | left, |
B, T, | “ |
right. |
| “ | O, 7, |
“ | C, S, |
“ | right, |
C, T, | “ |
left. |
| “ | U, 7, |
“ | C, S, |
“ | left, |
C, T, | “ |
right. |
These are all the various deflections which it is possible to give the
six needles. Those, however, which deflect to the right, not closing
the circuit, produce no effect, and are of no account. We will,
therefore, omit them, and simply give the table, thus:
| No.2. |
| The keys, | H, 7, |
move the arm | A, T, |
to the left. | No. |
1. |
| “ | J, 7, |
“ | A, S, |
“ | “ |
2. |
| “ | K, 7, |
“ | B, T, |
“ | “ |
3. |
| “ | M, 7, |
“ | B, S, |
“ | “ |
4. |
| “ | O, 7, |
“ | C, T, |
“ | “ |
5. |
| “ | U, 7, |
“ | C, S, |
“ | “ |
6. |
Fig. 75.
Birmingham.—Receiving Station.
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.
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.
Fig. 76.
Portsmouth.
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.
“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.
“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.”
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.
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.
Fig. 79.
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.
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]
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.
Transcriber's Notes:
Uncertain or antiquated spellings or ancient words were not corrected.
The illustrations and footnotes have been moved so that they do not break up
paragraphs and so that they are next to the text they illustrate.
Typographical errors have been silently corrected.
