The great secret of ubiquity, or at least of instantaneous
transmission, has ever exercised the ingenuity of mankind in various
romantic myths; and the discovery of certain properties of the
loadstone gave a new direction to these fancies.
The earliest anticipation of the Electric Telegraph of this purely
fabulous character forms the subject of one of the _Prolusiones
Academicæ_ of the learned Italian Jesuit Strada, first published at
Rome in the year 1617. Of this poem a free translation appeared in
1750. Strada’s fancy was this: “There is,” he supposes, “a species of
loadstone which possesses such virtue, that if two needles be touched
with it, and then balanced on separate pivots, and the one be turned in
a particular direction, the other will sympathetically move parallel
to it. He then directs each of these needles to be poised and mounted
parallel on a dial having the letters of the alphabet arranged round
it. Accordingly, if one person has one of the dials, and another the
other, by a little pre-arrangement as to details a correspondence can
be maintained between them at any distance by simply pointing the
needles to the letters of the required words. Strada, in his poetical
reverie, dreamt that some such sympathy might one day be found to hold
up the Magnesian Stone.”
Strada’s conceit seems to have made a profound impression on the
master-minds of the day. His poem is quoted in many works of the
seventeenth and eighteenth centuries; and Bishop Wilkins, in his book
on Cryptology, is strangely afraid lest his readers should mistake
Strada’s fancy for fact. Wilkins writes: “This invention is altogether
imaginary, having no foundation in any real experiment. You may see it
frequently confuted in those that treat concerning magnetical virtues.”
Again, Addison, in the 241st No. of the _Spectator_, 1712, describes
Strada’s “Chimerical correspondence,” and adds that, “if ever this
invention should be revived or put in practice,” he “would propose
that upon the lover’s dial-plate there should be written not only the
four-and-twenty letters, but several entire words which have always a
place in passionate epistles, as flames, darts, die, language, absence,
Cupid, heart, eyes, being, drown, and the like. This would very much
abridge the lover’s pains in this way of writing a letter, as it would
enable him to express the most useful and significant words with a
single touch of the needle.”
After Strada and his commentators comes Henry Van Etten, who shows how
“Claude, being at Paris, and John at Rome, might converse together, if
each had a needle touched by a stone of such virtue that as one moved
itself at Paris the other should be moved at Rome:” he adds, “it is
a fine invention, but I do not think there is a magnet in the world
which has such virtue; besides, it is inexpedient, for treasons would
be too frequent and too much protected. (_Recréations Mathématiques_:
see 5th edition, Paris, 1660, p. 158.) Sir Thomas Browne refers
to this “conceit” as “excellent, and, if the effect would follow,
somewhat divine;” but he tried the two needles touched with the same
loadstone, and placed in two circles of letters, “one friend keeping
one and another the other, and agreeing upon an hour when they will
communicate,” and found the tradition a failure that, “at what distance
of place soever, when one needle shall be removed unto any letter, the
other, by a wonderful sympathy, will move unto the same.” (See _Vulgar
Errors_, book ii. ch. iii.)
Glanvill’s _Vanity of Dogmatizing_, a work published in 1661, however,
contains the most remarkable allusion to the prevailing telegraphic
fancy. Glanvill was an enthusiast, and he clearly predicts the
discovery and general adoption of the electric telegraph. “To confer,”
he says, “at the distance of the Indies by sympathetic conveyance may
be as usual to future times as to us in a literary correspondence.” By
the word “sympathetic” he evidently intended to convey magnetic agency;
for he subsequently treats of “conference at a distance by impregnated
needles,” and describes the device substantially as it is given by Sir
Thomas Browne, adding, that though it did not then answer, “by some
other such way of magnetic efficiency it may hereafter with success be
attempted, when magical history shall be enlarged by riper inspection;
and ’tis not unlikely but that present discoveries might be improved
to the performance.” This may be said to close the most speculative or
mythical period in reference to the subject of electro-telegraphy.
Electricians now began to be sedulous in their experiments upon the
new force by friction, then the only known method of generating
electricity. In 1729, Stephen Gray, a pensioner of the Charter-house,
contrived a method of making electrical signals through a wire 765
feet long; yet this most important experiment did not excite much
attention. Next Dr. Watson, of the Royal Society, experimented on the
possibility of transmitting electricity through a large circuit from
the simple fact of Le Monnier’s account of his feeling the stroke
of the electrified fires through two of the basins of the Tuileries
(which occupy nearly an acre), by means of an iron chain lying upon
the ground and stretched round half their circumference. In 1745, Dr.
Watson, assisted by several members of the Royal Society, made a series
of experiments to ascertain how far electricity could be conveyed by
means of conductors. “They caused the shock to pass across the Thames
at Westminster Bridge, the circuit being completed by making use of the
river for one part of the chain of communication. One end of the wire
communicated with the coating of a charged phial, the other being held
by the observer, who in his other hand held an iron rod which he dipped
into the river. On the opposite side of the river stood a gentleman,
who likewise dipped an iron rod in the river with one hand, and in the
other held a wire the extremity of which might be brought into contact
with the wire of the phial. Upon making the discharge, the shock was
felt simultaneously by both the observers.” (_Priestley’s History of
Electricity._) Subsequently the same parties made experiments near
Shooter’s Hill, when the wires formed a circuit of four miles, and
conveyed the shock with equal facility,--“a distance which without
trial,” they observed, “was too great to be credited.”[52] These
experiments in 1747 established two great principles: 1, that the
electric current is transmissible along nearly two miles and a half of
iron wire; 2, that the electric current may be completed by burying the
poles in the earth at the above distance.
In the following year, 1748, Benjamin Franklin performed his celebrated
experiments on the banks of the Schuylkill, near Philadelphia; which
being interrupted by the hot weather, they were concluded by a picnic,
when spirits were fired by an electric spark sent through a wire in the
river, and a turkey was killed by the electric shock, and roasted by
the electric jack before a fire kindled by the electrified bottle.
In the year 1753, there appeared in the _Scots’ Magazine_, vol. xv.,
definite proposals for the construction of an electric telegraph,
requiring as many conducting wires as there are letters in the
alphabet; it was also proposed to converse by chimes, by substituting
bells for the balls. A similar system of telegraphing was next invented
by Joseph Bozolus, a Jesuit, at Rome; and next by the great Italian
electrician Tiberius Cavallo, in his treatise on Electricity.
In 1787, Arthur Young, when travelling in France, saw a model working
telegraph by M. Lomond: “You write two or three words on a paper,” says
Young; “he takes it with him into a room, and turns a machine enclosed
in a cylindrical case, at the top of which is an electrometer--a
small fine pith-ball; a wire connects with a similar cylinder and
electrometer in a distant apartment; and his wife, by remarking the
corresponding motions of the ball, writes down the words they indicate:
from which it appears that he has formed an alphabet of motions. As the
length of the wire makes no difference in the effect, a correspondence
might be carried on at any distance. Whatever the use may be, the
invention is beautiful.”
We now reach a new epoch in the scientific period--the discovery of the
Voltaic Pile. In 1794, according to _Voigt’s Magazine_, Reizen made
use of the electric spark for the telegraph; and in 1798 Dr. Salva
of Madrid constructed a similar telegraph, which the Prince of Peace
subsequently exhibited to the King of Spain with great success.
In 1809, Soemmering exhibited a telegraphic apparatus worked by
galvanism before the Academy of Sciences at Munich, in which the mode
of signalling consisted in the development of gas-bubbles from the
decomposition of water placed in a series of glass tubes, each of which
denoted a letter of the alphabet. In 1813, Mr. Sharpe, of Doe Hill near
Alfreton, devised a _voltaic_-electric telegraph, which he exhibited to
the Lords of the Admiralty, who spoke approvingly of it, but declined
to carry it into effect. In the following year, Soemmering exhibited a
_voltaic_-electric telegraph of his own construction, which, however,
was open to the objection of there being as many wires as signs or
letters of the alphabet.
The next invention is of much greater importance. Upon the suggestion
of Cavallo, already referred to, Francis Ronalds constructed a perfect
electric telegraph, employing frictional electricity notwithstanding
Volta’s discoveries had been known in England for sixteen years. This
telegraph was exhibited at Hammersmith in 1816:[53] it consisted of
a single insulated wire, the indication being by pith-balls in front
of a dial. When the wire was charged, the balls were divergent, but
collapsed when the wire was discharged; at the same time were employed
two clocks, with lettered discs for the signals. “If, as Paley asserts
(and Coleridge denies), ‘he alone discovers who proves,’ Ronalds is
entitled to the appellation of the first discoverer of an efficient
electric telegraph.” (_Saturday Review_, No. 147[54]) Nevertheless
the Government of the day refused to avail itself of this admirable
contrivance.
In 1819, Oersted made his great discovery of the deflection, by a
current of electricity, of a magnetic needle at right angles to such
current. Dr. Hamel of St. Petersburg states that Baron Schilling was
the first to apply Oersted’s discovery to telegraphy; Ampère had
previously suggested it, but his plan was very complicated, and Dr.
Hamel maintains that Schilling first realised the idea by actually
producing an electro-magnetic telegraph simpler in construction
than that which Ampère had _imagined_. In 1836, Professor Muncke of
Heidelberg, who had inspected Schilling’s telegraphic apparatus,
explained the same to William Fothergill Cooke, who in the following
year returned to England, and subsequently, with Professor Wheatstone,
laboured simultaneously for the introduction of the electro-magnetic
telegraph upon the English railways; the first patent for which was
taken out in the joint names of these two gentlemen.
In 1844, Professor Wheatstone, with one of his telegraphs, formed a
communication between King’s College and the lofty shot-tower on the
opposite bank of the Thames: the wire was laid along the parapets of
the terrace of Somerset House and Waterloo Bridge, and thence to the
top of the tower, about 150 feet high, where a telegraph was placed;
the wire then descended, and a plate of zinc attached to its extremity
was plunged into the mud of the river, whilst a similar plate attached
to the extremity at the north side was immersed in the water. The
circuit was thus completed by the entire breadth of the Thames, and the
telegraph acted as well as if the circuit were entirely metallic.
Shortly after this experiment, Professor Wheatstone and Mr. Cooke laid
down the first working electric telegraph on the Great Western Railway,
from Paddington to Slough.