HISTORY OF TELEGRAPHS,

_Employing Electricity in Various Ways for the Transmission of

Intelligence._

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.

[16] Many of the facts here given, are taken from Priestley’s Work upon

Electricity.

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_.”

[17] “As the possibility of this experiment has not been easily

conceived, I shall here describe it. Two iron rods, about three feet

long, were planted just within the margin of the river, on the opposite

sides. A thick piece of wire, with a small round knob at its end,

was fixed on the top of one of the rods, bending downwards, so as to

deliver commodiously the spark upon the surface of the spirit. A small

wire, fastened by one end to the handle of the spoon containing the

spirit, was carried across the river, and supported in the air by the

rope commonly used to hold by, in drawing ferry boats over. The other

end of this wire was tied round the coating of the bottle; which being

charged, the spark was delivered from the hook to the top of the rod

standing in the water on that side. At the same instant the rod on

the other side delivered a spark into the spoon and fired the spirit;

the electric fire returning to the coating of the bottle, through the

handle of the spoon and the supported wire connected with them.”

[18] “An electrified bumper is a small thin glass tumbler, nearly

filled with wine, and electrified as the bottle. This, when brought to

the lips, gives a shock, if the party be close shaved, and does not

breathe on the liquor.”

“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.

_Lomond’s Electrical Telegraph._

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.

_Reizen’s Electric Spark Telegraph._

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.

[Illustration: 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.

_Dr. Salva’s Electric Spark Telegraph._

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.

_Origin of Galvanism._

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.”

[Illustration: Fig. 35.]

_The Decomposition of Water._

“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.

_Samuel Thomas Soemmering’s Description of his Voltaic Electric

Telegraph, invented in 1809._

[Illustration: 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.”

[19] Academy of Sciences at Munich.

_Extract from the Journal of the Franklin Institute, vol. 20, page 325._

“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?”

_Ronald’s Electric Telegraph, invented in 1816. 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.

[Illustration: 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.”

_Electro Magnetism._

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_.

[20] Encyclopedia Britannica, vol. 21, p. 686.

“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.”

_The following Extract is taken from a Work on Electro Magnetism

published by Jacob Green, M. D. Professor of Chemistry in Jefferson

Medical College, 1827._

“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.

_Triboaillet’s Proposition._

[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.”

[21] Report of Academy of Industry, Paris.

_Fechner’s Suggestion._[22]

“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.

[22] Polytechnic Central Journal, 1838.

_Magneto Electricity._

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.”

[Illustration: 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.

[Illustration: 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.

[23] We here introduce to the reader our ingenious and scientific

country man, Mr. Joseph Saxton, formerly of the United States mint,

Philadelphia, but now connected with the Department of weights and

measures, at Washington, who invented the first Rotary Magneto Electric

Machine, and which has now been extensively adopted.

[Illustration: 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.”

[24] M. M. Nobili and Antinori.

[Illustration: 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.

[25] Mr. Saxton on the 3d of May exhibited his apparatus, and the

mode of obtaining the spark to Dr. Ritchie, Messrs. Thomas Gill, John

Isaac Hawkens and Steadman Whitwell. On the 8th of May he loaned it

to Dr. Ritchie, who publicly exhibited it at a lecture, at the London

University, and also at the London Institution, Finsbury.

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.

[26] In relation to this instrument, Prof. Daniell makes the following

remarks: “After Dr. Faraday’s discovery of _Volta electric_ and

_magneto electric_ induction, many ingenious contrivances were made for

exalting the effects and facilitating experiments. The most complete

arrangement now in use, was the original combination of Mr. Saxton.”

[Illustration: 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_.

[Illustration: 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.”

_Dr. Page’s Magneto Electric Machine._

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.

[Illustration: FIG. 45.]

[Illustration: 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.

[Illustration: 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.

_The Pole Changer._

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.

[Illustration: 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.

[Illustration: 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.

[Illustration: 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.

_Professor Morse’s American Electro Magnetic Telegraph, invented, 1832._

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.