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signal. We have noted that much attention was paid to communication by
sound-waves through the medium of the air from the earliest times. It
was not until the closing years of the past century, however, that
the superior possibilities of water as a conveyer of sound were
recognized.

Arthur J. Mundy, of Boston, happened to be on an American steamer on
the Mississippi River in the vicinity of New Orleans. It was rumored
that a Spanish torpedo-boat had evaded the United States war vessels
and made its way up the great river. The general alarm and the
impossibility of detecting the approach of another vessel set
Mundy thinking. It seemed to him that there should be some way
of communicating through the water and of listening for sounds
underwater. He recalled his boyhood experiments in the old
swimming-hole. He remembered how distinctly the sound of stones
cracked together carried to one whose ears were beneath the surface.
Thus the idea of underwater signaling was born.

Mundy communicated this idea to Elisha Gray, and the two, working
together, evolved a successful submarine signal system. It was on the
last day of the nineteenth century that they were able to put their
experiments into practical working form. Through a well in the center
of the ship they suspended an eight-hundred-pound bell twenty feet
beneath the surface of the sea. A receiving apparatus was located
three miles distant, which consisted simply of an ear-trumpet
connected to a gas-pipe lowered into the sea. The lower end of the
pipe was sealed with a diaphragm of tin. When submerged six feet
beneath the surface the strokes of the bell could be heard. Then
a special electrical receiver of extreme sensitiveness, known as a
microphone, was substituted and connected at the receiving station
with an ordinary telephone receiver. With this receiving apparatus the
strokes of the bell could be heard at a distance of over ten miles.

This system has had a wide practical application for communication
both between ship and ship and between ship and shore. Most
transatlantic ships are now equipped with such a system. The
transmitter consists of a large bell which is actuated either by
compressed air or by an electro-magnetic system. This is so arranged
that it may be suspended over the side of the ship and lowered
well beneath the surface of the water. The receivers consist of
microphones, one on each side of the ship. The telephone receivers
connected to the two microphones are mounted close together on an
instrument board on the bridge of the ship. The two instruments are
used when it is desired to determine the direction from which the
signals come. If the sound is stronger in the 'phone on the right-hand
side of the ship the commander knows that the signals are coming from
that direction. If the signals are from a ship in distress he may
proceed toward it by turning his vessel until the sound of the
signal-bell is equal in the two receivers. The ability to determine
the direction from which the signal comes is especially valuable
in navigating difficult channels in foggy weather. Signal-bells are
located near lighthouses and dangerous reefs. Each calls its own
number, and the vessel's commander may thus avoid obstructions and
guide the ship safely into the harbor. The submarine signal is equally
useful in enabling vessels to avoid collision in fogs. Because water
conducts sound much better than air, submarine signals are far better
than the fog-horn or whistles.

The submarine signal system has also been applied to submarine
war-ships. By this means alone may a submarine communicate with
another, with a vessel on the surface, or with a shore station.

An important and interesting adaptation of the marine signal was made
to meet the submarine warfare of the great European conflict. At first
it seemed that battle-ship and merchantman could find no way to locate
the approach of an enemy submarine. But it was found that by means
of the receiving apparatus of the submarine telephone an approaching
submarine could be heard and located. While the sounds of the
submarine's machinery are not audible above the water, the delicate
microphone located beneath the water can detect them. Hearing a
submarine approaching beneath the surface, the merchantman may avoid
her and the destroyers and patrol-boats may take means to effect her
capture.




III

FORERUNNERS OF THE TELEGRAPH

From Lodestone to Leyden Jar - The Mysterious "C.M." - Spark and
Frictional Telegraphs - The Electro-magnet - Davy and the Relay
System.


The thought and effort directed toward improving the means of
communication brought but small results until man discovered and
harnessed for himself a new servant - electricity. The story of
the growth of modern means of communication is the story of the
application of electricity to this particular one of man's needs.
The stories of the Masters of Space are the stories of the men who so
applied electricity that man might communicate with man.

Some manifestations of electricity had been known since long before
the Christian era. A Greek legend relates how a shepherd named Magnes
found that his crook was attracted by a strange rock. Thus was the
lodestone, the natural magnetic iron ore, discovered, and the legend
would lead us to believe that the words magnet and magnetism were
derived from the name of the shepherd who chanced upon this natural
magnet and the strange property of magnetism.

The ability of amber, when rubbed, to attract straws, was also known
to the early peoples. How early this property was found, or how, we do
not know. The name electricity is derived from _elektron_, the Greek
name for amber.

The early Chinese and Persians knew of the lodestone, and of the
magnetic properties of amber after it has been rubbed briskly. The
Romans were familiar with these and other electrical effects. The
Romans had discovered that the lodestone would attract iron, though a
stone wall intervened. They were fond of mounting a bit of iron on a
cork floating in a basin of water and watch it follow the lodestone
held in the hand. It is related that the early magicians used it as a
means of transmitting intelligence. If a needle were placed upon a bit
of cork and the whole floated in a circular vessel with the alphabet
inscribed about the circle, one outside the room could cause the
needle to point toward any desired letters in turn by stepping to the
proper position with the lodestone. Thus a message could be sent to
the magician inside and various feats of magic performed. Our own
modern magicians are reported as availing themselves of the more
modern applications of electricity in somewhat similar fashion and
using small, easily concealed wireless telegraph or telephone sets for
communication with their confederates off the stage.

The idea of encircling a floating needle with the alphabet was
developed into the sympathetic telegraph of the sixteenth century,
which was based on a curious error. It was supposed that needles which
had been touched by the same lodestone were sympathetic, and that if
both were free to move one would imitate the movements of another,
though they were at a distance. Thus, if one needle were attracted
toward one letter after the other, and the second similarly mounted
should follow its movements, a message might readily be spelled out.
Of course the second needle would not follow the movements of the
first, and so the sympathetic telegraph never worked, but much effort
was expended upon it.

In the mean time others had learned that many substances besides
amber, on being rubbed, possessed magnetic properties. Machines by
which electricity could be produced in greater quantities by friction
were produced and something was learned of conductors.

Benjamin Franklin sent aloft his historic kite and found that
electricity came down the silken cord. He demonstrated that frictional
and atmospheric electricity are the same. Franklin and others sent the
electric charge along a wire, but it did not occur to them to endeavor
to apply this to sending messages.

Credit for the first suggestion of an electric telegraph must be given
to an unknown writer of the middle eighteenth century. In the _Scots
Magazine_ for February 17, 1755, there appeared an article signed
simply, "C.M.," which suggested an electric telegraph. The writer's
idea was to lay an insulated wire for each letter of the alphabet.
The wires could be charged from an electrical machine in any desired
order, and at the receiving end would attract disks of paper marked
with the letter which that wire represented, and so any message could
be spelled out. The identity of "C.M." has never been established, but
he was probably Charles Morrison, a Scotch surgeon with a reputation
for electrical experimentation, who later emigrated to Virginia. Of
course "C.M.'s" telegraph was not practical, because of the many wires
required, but it proved to be a fertile suggestion which was followed
by many other thinkers. One experimenter after another added an
improvement or devised a new application.

A French scientist devised a telegraph which it is suspected might
have been practical, but he kept his device secret, and, as Napoleon
refused to consider it, it never was put to a test. An Englishman
devised a frictional telegraph early in the last century and
endeavored to interest the Admiralty. He was told that the semaphore
was all that was required for communication. Another submitted a
similar system to the same authorities in 1816, and was told that
"telegraphs of any kind are now wholly unnecessary." An American
inventor fared no better, for one Harrison Gray Dyar, of New York, was
compelled to abandon his experiments on Long Island and flee because
he was accused of conspiracy to carry on secret communication, which
sounded very like witchcraft to our forefathers. His telegraph sent
signals by having the electric spark transmitted by the wire decompose
nitric acid and so record the signals on moist litmus paper. It seems
altogether probable that had not the discovery of electro-magnetism
offered improved facilities to those seeking a practical telegraph,
this very chemical telegraph might have been put to practical use.

In the early days of the nineteenth century the battery had come into
being, and thus a new source of electric current was available for
the experimenters. Coupled with this important discovery in its
effect upon the development of the telegraph was the discovery of
electro-magnetism. This was the work of Hans Christian Oersted, a
native of Denmark. He first noticed that a current flowing through
a wire would deflect a compass, and thus discovered the magnetic
properties of the electric current. A Frenchman named Ampère,
experimenting further, discovered that when the electric current is
sent through coils of wire the magnetism is increased.

The possibility of using the deflection of a magnetic needle by
an electric current passing through a wire as a means of conveying
intelligence was quickly grasped by those who were striving for
a telegraph. Experiments with spark and chemical telegraphs were
superseded by efforts with this new discovery. Ampère, acting upon the
suggestion of La Place, an eminent mathematician, published a plan for
a feasible telegraph. This was later improved upon by others, and it
was still early in the nineteenth century that a model telegraph was
exhibited in London.

About this time two professors at the University of Göttingen were
experimenting with telegraphy. They established an experimental line
between their laboratories, using at first a battery. Then Faraday
discovered that an electric current could be generated in a wire by
the motion of a magnet, thus laying the basis for the modern dynamo.
Professors Gauss and Weber, who were operating the telegraph line at
Göttingen, adapted this new discovery to their needs. They sent the
message by moving a magnetic key. A current was thus generated in the
line, and, passing over the wire and through a coil at the farther
end, moved a magnet suspended there. The magnet moved to the right or
left, depending on the direction of the current sent through the
wire. A tiny mirror was mounted on the receiving magnet to magnify its
movement and so render it more readily visible.

One Steinheil, of Munich, simplified it and added a call-bell. He
also devised a recording telegraph in which the moving needle at the
receiving station marked down its message in dots and dashes on a
ribbon of paper. He was the first to utilize the earth for the return
circuit, using a single wire for despatching the electric current used
in signaling and allowing it to return through the ground.

In 1837, the same year in which Wheatstone and Morse were busy
perfecting their telegraphs, as we shall see, Edward Davy exhibited a
needle telegraph in London. Davy also realized that the discoveries
of Arago could be used in improving the telegraph and making it
practical. Arago discovered that the current passing through a coil of
wire served to magnetize temporarily a piece of soft iron within it.
It was this principle upon which Morse was working at this time. Davy
did not carry his suggestions into effect, however. He emigrated to
Australia, and the interruption in his experiments left the field open
for those who were finally to bring the telegraph into usable form.
Davy's greatest contribution to telegraphy was the relay system by
which very weak currents could call into play strong currents from
a local battery, and so make the signals apparent at the receiving
station.




IV


INVENTIONS OF SIR CHARLES WHEATSTONE

Wheatstone and His Enchanted Lyre - Wheatstone and Cooke - First
Electric Telegraph Line Installed - The Capture of the "Kwaker" - The
Automatic Transmitter.


Before we come to the story of Samuel F.B. Morse and the telegraph
which actually proved a commercial success as the first practical
carrier of intelligence which had been created for the service of man,
we should pause to consider the achievements of Charles Wheatstone.
Together with William Fothergill Cooke, another Englishman, he
developed a telegraph line that, while it did not attain commercial
success, was the first working telegraph placed at the service of the
public.

Charles Wheatstone was born near Gloucester in 1802. Having completed
his primary schooling, Charles was apprenticed to his uncle, who was
a maker and seller of musical instruments. He showed little aptitude
either in the workshop or in the store, and much preferred to continue
the study of books. His father eventually took him from his uncle's
charge and allowed him to follow his bent. He translated poetry from
the French at the age of fifteen, and wrote some verse of his own. He
spent all the money he could secure on books. Becoming interested in a
book on Volta's experiments with electricity, he saved up his coppers
until he could purchase it. It was in French, and he found the
technical descriptions rather too difficult for his comprehension, so
that he was forced to save again to buy a French-English dictionary.
With the aid of this he mastered the volume.

Immediately his attention was turned toward the wonders of the infant
science of electricity, and he eagerly endeavored to perform the
experiments described. Aided by his older brother, he set to work on
a battery as a source of current. Running short of funds with which to
purchase copper plates, he again began to save his pennies. Then the
idea occurred to him to use the pennies themselves, and his first
battery was soon complete.

He continued his experiments in various fields until, at the age of
nineteen, he first brought himself to public notice with his enchanted
lyre. This he placed on exhibition in music-shops in London. It
consisted of a small lyre suspended from the ceiling which gave forth,
in turn, the sounds of various musical instruments. Really the lyre
was merely a sounding-box, and the vibrations of the music were
conveyed from instruments, played in the next room, to the lyre
through a steel rod. The young man spent much time experimenting with
the transmission of sound. Having conveyed music through the steel rod
to his enchanted lyre, much to the mystification of the Londoners,
he proposed to transmit sounds over a considerable distance by this
method. He estimated that sound could be sent through steel rods at
the rate of two hundred miles a second and suggested the use of such
a rod as a telegraph between London and Edinburgh. He called his
arrangement a telephone.

A scientific writer of the day, commenting in a scientific journal
on the enchanted lyre which Wheatstone had devised, suggested that it
might be used to render musical concerts audible at a distance. Thus
an opera performed in a theater might be conveyed through rods to
other buildings in the vicinity and there reproduced. This was never
accomplished, and it remained for our own times to accomplish this and
even greater wonders.

Wheatstone also devised an instrument for increasing feeble sound,
which he called a microphone. This consisted of a pair of rods to
convey the sound vibrations to the ears, and does not at all resemble
the modern electrical microphone. Other inventions in the transmission
and reproduction of sound followed, and he devoted no little attention
to the construction of improved musical instruments. He even made some
efforts to produce a practical talking-machine, and was convinced
that one would be attained. At thirty-two he was widely famed as a
scientist and had been made a professor of experimental physics
in King's College, London. His most notable work at this time was
measuring the speed of the electric current, which up to that time had
been supposed to be instantaneous.

By 1835 Wheatstone had abandoned his plans for transmitting sounds
through long rods of metal and was studying the telegraph. He
experimented with instruments of his own and proposed a line across
the Thames. It was in 1836 that Mr. Cooke, an army officer home on
leave, became interested in the telegraph and devoted himself to
putting it on a working basis. He had already exhibited a crude set
when he came to Wheatstone, realizing his own lack of scientific
knowledge. The two men finally entered into partnership, Wheatstone
contributing the scientific and Cooke the business ability to the new
enterprise. The partnership was arranged late in 1837, and a patent
taken out on Wheatstone's five-needle telegraph.

In this telegraph a magnetic needle was located within a loop formed
by the telegraph circuit at the receiving end. When the circuit was
closed the needle was deflected to one side or the other, according to
the direction of the current. Five separate circuits and needles were
used, and a variety of signals could thus be sent. Five wires, with a
sixth return wire, were used in the first experimental line erected in
London in 1837. So in the year when Morse was constructing his models
Wheatstone and Cooke were operating an experimental line, crude
and impracticable though it was, and enjoying the sensations of
communicating with each other at a distance.

In 1841 the telegraph was placed on public exhibition at so much a
head, but it was viewed as an entertaining novelty without utility by
the public at large. After many disappointments the inventors secured
the cooperation of the Great Western Railroad, and a line was erected
for a distance of thirteen miles. But the public would not patronise
the line until its utility was strikingly demonstrated by the capture
of the "Kwaker."

Early one morning a woman was found dead in her home in the suburbs of
London. A man had been observed leaving the house, and his appearance
had been noted. Inquiries revealed that a man answering his
description had left on the slow train for London. Without the
telegraph he could not have been apprehended. But the telegraph was
available at this point, and his description was telegraphed ahead and
the police in London were instructed to arrest him upon his arrival.
"He is dressed as a Quaker," ran the message. There was no Q in the
alphabet of-the five-needle instrument, and so the sender spelled
Quaker, Kwaker. The clerk at the receiving end could not-understand
the strange word, and asked to have it repeated again and again.
Finally some one suggested that the message be completed and the whole
was then deciphered. When the man dressed as a Quaker stepped from the
slow train on his arrival at London the police were awaiting him; he
was arrested and eventually confessed the murder. The news of this
capture and the part the telegraph played gave striking proof of the
utility of the new invention, and public skepticism and indifference
were overcome.

By 1845 Wheatstone had so improved his apparatus that but one wire was
required. The single-needle instrument pointed out the letters on the
dial around it by successive deflections in which it was arranged
to move, step by step, at the will of the sending station. The
single-needle instrument, though generally displaced by Morse's
telegraph, remained in use for a long time on some English lines.
Wheatstone had also invented a type-printing telegraph, which he
patented in 1841. This required two circuits.

With a working telegraph attained, the partners became involved in an
altercation as to which deserved the honor of inventing the same.
The quarrel was finally submitted to two famous scientists for
arbitration. They reported that the telegraph was the result of
their joint labors. To Wheatstone belongs the credit for devising
the apparatus; to Cooke for introducing it and placing it before the
public in working form. Here we see the combination of the man of
science and the man of business, each contributing needed talents for
the establishment of a great invention on a working basis.

Wheatstone's researches in the field of electricity were constant.
In 1840 he devised a magnetic clock and proposed a plan by which many
clocks, located at different points, could be set at regular intervals
with the aid of electricity. Such a system was the forerunner of
the electrically wound and regulated clocks with which we are now so
familiar. He also devised a method for measuring the resistance which
wires offer to the passage of an electric current. This is known
as Wheatstone's bridge and is still in use in every electrical and
physical laboratory. He also invented a sound telegraph by which
signals were transmitted by the strokes of a bell operated by the
current at the receiving end of the circuit.

The invention of Wheatstone's which proved to be of greatest lasting
importance in connection with the telegraph was the automatic
transmitter. By this system the message is first punched in a strip of
paper which, when passed through the sending instrument, transmits the
message. By this means he was able to send messages at the rate of one
hundred words a minute. This automatic transmitter is much used for
press telegrams where duplicate messages are to be sent to various
points.

The automatic transmitter brought knighthood to its inventor,
Wheatstone receiving this honor in 1868. Wheatstone took an active
part in the development of the telegraph and the submarine cable up to
the time of his death in 1875.

Wheatstone's telegraph would have served the purposes of humanity
and probably have been universally adopted, had not a better one been
invented almost before it was established. And it is because Morse,
taking up the work where others had left off, was able to invent an
instrument which so fully satisfied the requirements of man for so
long a period that he is known to all of us as the inventor of the
telegraph. And yet, without belittling the part played by Morse,
we must recognize the important work accomplished by Sir Charles
Wheatstone.




V

THE ACHIEVEMENT OF MORSE

Morse's Early Life - Artistic Aspirations - Studies in Paris - His
Paintings - Beginnings of His Invention - The First Instrument - The
Morse Code - The First Written Message.


When we consider the youth and immaturity of America in the first half
of the nineteenth century, it seems the more remarkable that the honor
of making the first great practical application of electricity should
have been reserved for an American. With the exception of the isolated
work of Franklin, the development of the new science of electrical
learning was the work of Europeans. This was natural, for it was
Europe which was possessed of the accumulated wealth and learning


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