CHAPTER X.

THE ELECTRIC TELEGRAPH.

In the year 1617 Strada, an Italian Jesuit, proposed to telegraph news

without wires by means of two sympathetic needles made of loadstone so

balanced that when one was turned the other would turn with it. Each

needle was to have a dial with the letters on it. This would have been

very nice if it had only worked, but it was not based on any known law

of nature.

Many attempts at telegraphing with electricity were made by different

people during the eighteenth century. About 1748 Franklin succeeded in

firing spirits by means of a wire across the Schuylkill River, using, as

all the other experimenters had done, frictional electricity. In 1753 an

anonymous letter was written to Scott's Magazine describing a method by

which it was possible to communicate at a distance by electricity. The

writer proposed the use of a wire for each letter of the alphabet, that

should terminate in pith balls at the receiving end, and under the balls

were to be strips of paper corresponding to the letters of the

alphabet. The message was to be sent by discharging static electricity

through the wire corresponding to the first letter of a word when the

paper would be attracted to the pith ball and read by the observer. Then

the wire corresponding to the second letter of the word was to be

charged in like manner, and so on till the whole message was spelled

out. This was the first practical (i.e., possible) suggestion for a

telegraph. The writer also proposed to have the wires strung on

insulators, which was a great advance over the other attempts.

The communication was anonymous, as no doubt, like many others, the

author feared the ridicule of his neighbors. It requires a vast amount

of moral courage to stand up before the world and openly advocate some

new theory that has never come within the experience of any one before.

It requires much now, but it required more then; for a man in those days

would have been roasted for what in these days he would be toasted. The

rank and file of humanity have been opposed to innovations in all ages,

but no progress could have been made without innovations. There always

has to be a first time. Galileo is said to have been forced to retract,

on his knees, some theory he advanced about the motion of the earth, and

its relation to the sun and other heavenly bodies. Notwithstanding this

retraction the seed-thought sown by Galileo took root in other minds,

which led to the triumph of scientific truth over religious fanaticism.

The writer in Scott's Magazine did not have the opportunity to put his

ideas into practice, so the glory of the invention fell to others. Such

men as this unknown writer are made of finer stuff, and they stand alone

on the frontier of progress. They do not fear the bullets of an enemy

half so much as the gibes of a friend. Much of their work is done

quietly and without notice, and when something of real importance is

worked out theoretically and experimentally, some one seizes upon it and

proclaims it from the housetops and attaches to it his name; but perhaps

years after the real inventor (the man who taught the so-called inventor

how to do it) is dead, some one writes a book that reveals the truth,

and then the hero-loving people erect a monument to his memory.

Such a man was our own Professor Joseph Henry, so long the presiding

genius at the Smithsonian Institution at Washington. He worked out all

the problems of the present American telegraphic system and demonstrated

it practically. Everything that made the so-called Morse telegraph a

success had long before been described and demonstrated by Henry. Yet

with the modest grace that was ingrained in the man he yielded all to

the one who was instrumental in constructing the first telegraph line

between Baltimore and Washington. Great credit is due to such men as

Morse and Cyrus W. Field--neither of them inventors, but promoters of

great systems of communication that are of unspeakable benefit to

mankind. Henry pointed out the way, and Morse carried it into effect.

Morse has had no more credit than was due him, but has Henry had as much

as is due him? No great invention was ever yet the work, wholly, of one

man. We Americans are too apt to forget this.

I shall always remember Henry as a most unassuming, kindly, genial man,

and I shall never forget his kindness to me. In 1874 I began my

researches in telephony, having applied for a patent for an apparatus

for transmitting musical tones telegraphically. This consisted of a

means of transmitting musical tones through a wire and reproducing them

on a metal plate (stretched on the body of a violin to give it

resonance) by rubbing the plate with the hand--the latter being a part

of the circuit. The examiner refused the application at first on the

ground that the inventor or operator could not be a part of his machine.

I took my apparatus and went to Washington, first calling upon Professor

Henry, never having met him before. He received me most kindly, and

allowed me to string wires from room to room in the institute, and when

he had witnessed the experiments he seemed as delighted as a child. I

now brought the patent office official over to the Smithsonian and soon

convinced him that the inventor could be a part of his own machine.

The same year I went abroad, and Henry gave me a letter to Tyndall. It

was very fortunate for me that he did, for Tyndall was very shy at

first, and it was only Henry's letter that gave me a hearing for a

moment. The history of the few days that followed this first interview

with Tyndall at the Royal Institution would make very interesting

reading, if I felt at liberty to publish it. Suffice it to say that he

was convinced in a few minutes after he had reached the experimental

stage that not all my work had been anticipated by Wheatstone, as he

asserted before seeing the experiments. Wheatstone had transmitted the

tones of a piano, mechanically, from one room to another by a wooden rod

placed upon the sound-board and terminating in another room in contact

with another sound-board. But this was very different from transmitting

musical tones and melodies from one city to another through a wire, as I

could do with my electrotelephonic apparatus.

It is a curious fact that the world is divided into two great classes,

leaders and followers. Or we might say, originators and copyists; the

former division being very small, while the latter is very large. As

late as 1820 the European philosophers were trying to construct a

telegraphic system based upon two ideas, announced a long time before,

to wit, the use of static or frictional electricity, and a wire for

every letter. It does not seem to have occurred to any one to devise a

code consisting of motions differently related as to time, and to use

simply one wire.

In 1819 Oersted discovered the effect of a galvanic current on a

magnetic needle, and published a pamphlet concerning his discovery. This

stimulated others, and Ampere applied it to the galvanometer the same

year. Arago applied it to soft iron, and here was the germ of the

electromagnet. We see that as far back as 1820 we had the galvanic

battery and the electromagnet, the two great essentials of the modern

telegraph.

However, there remained another great discovery to be made before these

elements could be utilized for telegraphic purposes. One cell of battery

was used, and the magnet was made by winding one layer of wire spirally

around the iron, so that each spiral was out of touch with its neighbor.

Barlow of England, a Fellow of the Royal Society, tried the effect of a

current through a wire 200 feet long, and found that the power was so

diminished that he was discouraged, and in a paper gave it as his

opinion that galvanism was of no use for telegraphing at a distance.

This paper stimulated others, and it was reserved for our own Joseph

Henry, already referred to, to show not only how to construct a magnet

for long-distance telegraphy, but also how to adapt the battery to the

distance. He showed us that by insulating the wire and using several

layers of whirls, instead of one, and by using enough cells of battery

coupled up in series to get more voltage, as we now express it, it was

possible to transmit signals to a distance. He not only set forth the

theory, but he constructed a line of bell-wire 1060 feet long and worked

his magnet by making the armature strike a bell for the signals, which

is the basis of the modern "sounder."

Nothing was needed but to construct a line and devise a code to be read

by sound, to have practically our modern Morse telegraph. This line was

constructed in 1831. In 1835 Henry, who was then at Princeton,

constructed a line and worked it as it is to-day worked, with a relay

and local circuit, so that at that period all the problems had been

worked out. But, like the speaking-telephone in its early inception, no

one appreciated its real importance. Henry himself did not think it

worth while to take out a patent. Two years later the Secretary of the

Treasury sent out a circular letter of inquiry to know if some system of

telegraphic communication could not be devised. The learned heads of

the Franklin Institute of Philadelphia, the oldest scientific society in

America, advised that a semaphore system be established between New York

and Washington, consisting of forty towers with swinging arms, the same

as used in the days of Wellington. Among other replies to the circular

letter of the secretary was one from Samuel F. B. Morse. Morse was not a

scientist or even an inventor, at least not at that time. He was an

artist of some note. In 1832, while crossing the ocean, Morse, in

connection with one Dr. Jackson of Boston, devised a code of telegraphic

signs intended to be used in a chemical telegraph system.

Some years later Morse adapted Henry's signal-instrument to a recorder,

called the Morse register, and this was the instrument used in the early

days of the Morse telegraph.

What Morse seems to have really invented was the register, which made

embossed marks on a strip of paper, and the code of dots and dashes

representing letters, now known as the Morse alphabet, although this

latter is questioned. Morse took his apparatus to Washington and

exhibited it to the members of Congress in the year 1838, but it was

four years before a bill was passed that enabled him to try the

experiment between Baltimore and Washington. We will let him describe in

his own words the closing day of Congress. He says:

"My bill had indeed passed the House of Representatives and it was on

the calendar of the Senate, but the evening of the last day had

commenced with more than 100 bills to be considered and passed upon

before mine could be reached. Wearied out with the anxiety of suspense,

I consulted one of my senatorial friends. He thought the chance of

reaching it to be so small that he advised me to consider it as lost. In

a state of mind which I must leave you to imagine, I returned to my

lodgings to make preparations for returning home the next day. My funds

were reduced to the fraction of a dollar. In the morning, as I was about

to sit down to breakfast, the servant announced that a young lady

desired to see me in the parlor. It was the daughter of my excellent

friend and college classmate, the commissioner of patents, Henry L.

Ellsworth. She had called, she said, by her father's permission, and in

the exuberance of her own joy, to announce to me the passage of my

telegraph bill at midnight, but a moment before the Senate adjourned.

This was the turning-point of the telegraph invention in America. As an

appropriate acknowledgment of the young lady's sympathy and kindness--a

sympathy which only a woman can feel and express--I promised that the

first dispatch by the first line of telegraph from Washington to

Baltimore should be indited by her; to which she replied: 'Remember,

now, I shall hold you to your word.' About a year from that time the

line was completed, and, everything being prepared, I apprised my young

friend of the fact. A note from her inclosed this dispatch: 'What hath

God wrought?' These were the first words that passed on the first

completed line in America."

The first telegraph-line in America was put into operation in the spring

of 1844 at the beginning of Polk's administration. I remember as a boy

having the two cities, Baltimore and Washington, pointed out to me on

the map, and how the story of the telegraph impressed me. Congress

appropriated $30,000 for the construction of the line, and $8000 to keep

it running the first year. It was placed under the control of the

postmaster-general, and the line was thrown open to the public. The

tariff was fixed at one cent for every four words. It was open for

business on April 1, 1844, and for the first few days the revenue was

exceedingly small. On the morning of the first day a gentleman came in

and wanted to "see it work." The operator told him that he would be glad

to show it at the regular tariff of one cent for four words. The

gentleman grew angry and said that he was influential with the

administration, and that if he did not show him the working free of

charge he would see to it that he lost his job. His bluff did not

succeed. The operator referred him to the postmaster-general, and thus

the stormy interview ended. No patrons came in for the next three days,

but a great number stood around hoping to see the instrument start up,

but no one was willing to invest a cent--probably from fear of being

laughed at.

On the fourth day the same gentleman who had threatened the young man

with dismissal came back and invested a cent, and this was the first and

only revenue for four days. The message that was sent only came to

one-half cent, but as the operator could not make change the stranger

laid down the cent and departed. His name ought to be known to fame as

the first man patron of the telegraph.

[Illustration: Fig. 2.

A gives a diagram view of a Morse telegraph-line with three

stations. B is the battery; C C C, the transmitting keys in the

three offices; D D D, the relay magnets; E E E, the armatures

that are actuated by the magnets.]

The operation of the Morse telegraph is very simple if we grant all that

has gone before. All that is needed is the wire, the battery, and the

key, as shown in Fig. 2 (page 99), and a relay--an extra electromagnet

which receives the electric current and by its means puts into or out of

action a small local battery on a short circuit in which is placed the

receiving or recording apparatus. Thus we have a wire starting from the

earth in New York and passing through a battery, a key and a relay, and

thence to Boston on poles, with insulators on which the wire is strung,

and through another instrument, key and battery in Boston, the same as

at the New York end, and into the ground, leaving the earth to complete

one-half of the circuit. When the keys at both ends are closed the

batteries are active and the armatures or "keepers" are attracted so

that the armature levers rest on the forward stops. (See diagram Fig.

2.) If either one of the keys is opened the current stops flowing and

the magnetism vanishes from all the electromagnets on the line, and a

spring or retractile of some kind pulls the armatures away from the

magnets and the levers rest on their back stops. In this way all the

levers of all the magnets are made to follow the motions of any key. If

there are more than two magnets in circuit (and there may be twenty or

more) they all respond in unison to the working of one key, so that when

any one station is sending a dispatch all the other stations get it.

But there is a "call" for each office, so that the operator only heeds

the instrument when he hears his own call. Operators become so expert in

reading by sound that they may lie down and sleep in the room, and,

although the instrument is rattling away all the time, he does not hear

it till his own call is made, when he immediately awakes.

In the old days messages were received on slips of paper by the Morse

register by means of dots and dashes. Gradually the operator learned to

read by sound, till now this mode of receiving is almost universal the

world over. Reading by sound was of American origin. It is a spoken

language, and when one becomes accustomed to it it is like any other

language. This code language has some advantages over articulate speech,

as well as many disadvantages. A gentleman who was connected with a

Louisville telegraph office told me that one of the best operators he

ever knew was as deaf as a post. He would receive the message by holding

his knee against the leg of the table upon which the sounder was

mounted, and through the sense of feeling receive the long and short

vibrations of the table, and by this means read as well or better than

through the ear, because he was not distracted by other sounds.

A story is told of the late General Stager that at one time he was on a

train that was wrecked at some distance from any station. He climbed a

telegraph pole, cut the wire and by alternately joining and separating

the ends sent a message, detailing the story of the wreck, to

headquarters, and asked for assistance. He then held the two ends of the

wire on each side of his tongue and tasted out the reply--that help was

coming. Any one who has ever tasted a current knows that it is very

pronounced.

A story similar to this is told of the early days when the Bain chemical

system was used between Washington City and some other point. This

system made marks on chemically-prepared paper; as the current passed

through it left marks on the paper from the decomposition of the

chemicals. Some of the preparations emitted an odor during the time that

the current passed. The occurrence to which we refer took place at

presidential election time. At some station out of Washington an

operator was employed who had a blind sister, and this sister knew the

Morse alphabet well before she became blind. One evening a signal came

to get ready for a message containing the returns from the election. In

the hurry, and just as the message had started, the lamp was upset and

they were in total darkness--at least, the brother was. The sister, poor

girl, had been in darkness a long time. The blind sister leaned over the

stylus through which the current flowed to the paper and smelled out as

well as spelled out the message, and repeated it to her astonished

brother.

By the old semaphore system the motions were sensed through the eye as

well as the early method of cable signaling. It will be seen from the

above that the Morse code may be communicated through any one of the

five senses.

Electricity and Magnetism · 第 10 / 29 章