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Wm. H. (William Henry) Meadowcroft.

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Court.

A busier shop than that of the young in-
ventor during the years 1870 to 1874 would be
difficult to find. Not only was he and it
engaged on the tremendous problems of the
automatic and quadruplex systems, but the
shop was also busy making stock tickers. The
hours were endless ; and on one occasion when
an order was on hand for a large quantity of
these instruments Edison locked the men in
until the job had been finished of making the
machine perfect, and " all the bugs taken out,"
which meant sixty hours of hard work before
the difficulties were overcome.



A BUSY YOUNG INVENTOR

In addition to all this work, Edison gave
attention to many other things. One of them
was the first typewriter. In the early seven-
:ies Mr. D. N. Craig, who was interested in
:he automatic, brought with him from Mil-
waukee a Mr. Sholes, who had a wooden
nodel of a machine to which had been given
;he then new and unfamiliar name of " type-
writer. " Mr. Craig was interested in the
nachine and put the model in Edison's hands
;o perfect.

"This typewriter proved a difficult thing/'
;ays Edison, "to make commercial. The
dignment of the letters was awful. One
etter would be one-sixteenth of an inch above
;he others, and all the letters wanted to wan-
ler out of line. I worked on it till the machine
*ave fair results. Some were made and used
n the office of the Automatic Company,
raig was very sanguine that some day all
business letters would be written on a type-
writer. He died before that took place; but
it gradually made its way. The typewriter
I got into commercial shape is now known as
the Remington. I now had five shops, and
with experimenting on this new scheme I



THE BOY'S LIFE OF EDISON

was pretty busy at least I did not have



ennui.'



Later on, after the automatic was com-
pleted, and Edison was installing the system
for the Atlantic and Pacific Telegraph Com-
pany he says: " About this time I invented a
district messenger call-box system, and organ-
ized a company called^the Domestic Telegraph
Company, and started in to install the system
in New York. I had great difficulty in getting
subscribers, having tried several canvassers,
who, one after the other, failed to get sub-
scribers. When I was about to give it up a
test operator named Brown, who was on the
Automatic Telegraph wire between New York
and Washington, which passed through my
Newark shop, asked permission to let him try
and see if he couldn't get subscribers. I had
very little faith in his ability to get any, but I
thought I would give him a chance, as he felt
certain of his ability to succeed. He started
in, and the results were surprising. Within
a month he had procured two hundred sub-
scribers, and the company was a success. I
have never quite understood why six men
should fail absolutely, while the seventh man



A BUSY YOUNG INVENTOR

should succeed. Perhaps hypnotism would
account for it. This company was sold out
to the Atlantic and Pacific Company."

This was not the first time that Edison had
worked on district messenger signal boxes, for
as far back as 1872 he had applied for a patent
on a device of this kind. Although he was not
the first, he was a very early inventor in this
field.

It will be seen, therefore, that not all of his
problems and inventions were connected with
telegraphy. He seemed to find relief in work-
ing on several lines that were quite different
and distinct, but all were useful and capable
of wide application. For instance, when we
take a piece of paraffin paper off candy,
chocolate, chewing-gum or other articles, we
scarcely realize that it owes its introduction
to Mr. Edison. Yet such is the fact, and we
relate it in his own modest words: " To ward
the latter part of 1875, in the Newark shop,
I invented a device for multiplying copies of
letters, which I sold to Mr. A. B. Dick, of
Chicago, and in the years since it has been
introduced universally throughout the world,
tt is called the mimeograph. I also invented



THE BOY'S LIFE OF EDISON

devices for making, and introduced, paraffin
paper, now used universally for wrapping up
candy, etc."

In the mimeograph a stencil is prepared by
writing with a pointed pencil-like stylus on a
tough prepared paper placed on a finely
grooved steel plate. The pressure of the
stylus causes the letters to be punctured in
the sheet by a series of minute perforations,
thus forming a stencil from which hundreds of
copies can be made.

Edison accomplished the same perforating
result by two other inventions, one a pneu-
matic and the other an electric motor. The
latter was the one which came into extensive
use, and was called the "Edison electric
pen." A tiny electric motor was mounted on
a pencil-like tube in which a pointed stylus
(connected to the motor) traveled to and fro
at a very high rate of speed. Current from a
battery was supplied to the motor through a
flexible cord, and the tube was held and used
like a pencil, as in the other case. As many
as three thousand copies have been made from
such a stencil.



XI

THE TELEPHONE, MOTOGRAPH, AND MICROPHONE

TT is well known that to Mr. Alexander
* Graham Bell belongs the credit for trans-
mitting the articulate voice over an electric
circuit by talking against a diaphragm placed
in front of an electro-magnet. But after
Mr. Bell brought out the telephone Mr.
Edison made some remarkable improvements.

In the year 1875 Edison took up the study
of harmonic telegraphs, in addition to his
other work, with the idea of developing a
system of multiple transmission by sending
sound waves over an electric circuit.

One of the devices he then made is illus-
trated in an interesting drawing on file at the
Orange Laboratory, entitled " First Telephone
on Record." This device is described by
Edison in a caveat filed in the Patent Office
January 14, 1876, a month before Bell filed his
application for patent.



THE BOY'S LIFE OF EDISON

Mr. Edison states, however, that while
this device was crudely capable of use as a
magneto telephone, he did not invent it for
transmitting speech, but as an apparatus for
analyzing the complex waves arising from
various sounds. He did not try the effects of
sound waves produced by the human voice
until after Bell's discovery was announced,
but then found that this device was capable of
use as a telephone.

This was a curious coincidence, but it must
be understood that Mr. Edison in his testi-
mony and public utterances has always given
Mr. Bell full credit for the original discovery
of transmitting articulate speech over an
electric circuit.

In order to understand the value of Edison's
work in this field it should be stated that, while
Bell's telephone transmitted speech and other
sounds, it was only practicable for short lines.
Bell had no separate transmitter, but used a
single apparatus both as transmitter and
receiver. This instrument was similar to the
receiver used to-day, having a metallic dia-
phragm placed near the pole of a magnet.
The vibrations of the diaphragm induced very

1 60



THE TELEPHONE

weak electric impulses in the magnetic coil.
These impulses passed over the line to the
receiving end, energizing the magnet coil
there, and, by varying the magnetism, caused
the receiving diaphragm to be similarly
vibrated, and thus reproduce the sounds.
Under such conditions the telephone would
be practicable upon lines of only a few miles
in extent, as the amount of power generated
by the human voice is necessarily quite
limited.

The Western Union Company requested
Edison to experiment on the telephone so
that it would be commercially practicable.
He then went to work with a corps of helpers,
and, after months of hard work day and night
and the performance of many thousands of
experiments, invented the carbon transmitter.

This, with his plan of using an induction coil
and constant battery current on the line, were
the needed elements of success, and it made
the telephone a commercial possibility. Every
one of the many millions of telephones in use
all over the world to-day bears the imprint of
Edison's genius in the employment of th
principles he then established.



THE BOY'S LIFE OF EDISON

What Edison accomplished was this: In-
stead of using one single apparatus for trans-
mitting and receiving, he made a separate
transmitter of special design. In this he used
carbon, which varies in electrical resistance
with the pressure applied. The carbon was
an electrode in connection with the vibrating
diaphragm, and was in a closed circuit through
which flowed a battery current. The vibra-
tions of the diaphragm caused variations of
pressure on the carbon and consequent varia-
tions in the current. These in turn resulted
in corresponding impulses in the receiving
magnet, and the diaphragm of the receiver
was vibrated accordingly, thus reproducing
the sounds. Edison's plan also included the
passing of the current through an induction
coil, the secondary of which was connected
with the main line. By this means electrical
impulses of enormously high potential are
sent out on the main line to the receiving end.

Thus it will be seen that with Bell's tele-
phone the sound-waves themselves generate
the electric impulses, which are hence ex-
tremely weak. With Edison's telephone the
sound-waves actuate an electric valve, so to

162



THE TELEPHONE

speak, and permit variations in a current of
any desired strength.

Mr. Edison's own story of his telephone
work is full of interest: "In 1876 I started
again to experiment for the Western Union
and Mr. Orton. This time it was the tele-
phone. Bell invented the first telephone,
which consisted of the present receiver, used
both as a transmitter and a receiver (the
magneto type). It was attempted to intro-
duce it commercially, but it failed on account
of its faintness and the extraneous sounds
which came in on its wire from various causes.
Mr. Orton wanted me to take hold of it and
make it commercial. As I had also been
working on a telegraph system employing
tuning-forks, simultaneously with both Bell
and Gray, I was pretty familiar with" the sub-
ject. I started in, and soon produced the car-
bon transmitter, which is now universally used.

" Tests were made between New York and
Philadelphia, also between New York and
Washington, using regular Western Union
wires. The noises were so great that not a
word could be heard with the Bell receiver
when used as a transmitter between New York

163



THE BOY'S LIFE OF EDISON

and Newark, New Jersey. Mr. Orton and
W. K. Vanderbilt and the board of directors
witnessed and took part in the tests of my
transmitter. They were successful. The
Western Union then put the transmitters on
private lines. Mr. Theodore Puskas, of Buda-
pest, Hungary, was the first man to suggest
a telephone exchange, and soon after ex-
changes were established. The telephone de-
partment was put in the hands of Hamilton
McK. Twombly, Vanderbilt 's ablest son-in-
law, who made a success of it. The Bell
Company, of Boston, also started an exchange,
and the fight was on, the Western Union
pirating the Bell receiver and the Boston
company pirating the Western Union trans-
mitter. About this time I wanted to be
taken care of. I threw out hints of this
desire. Then Mr. Orton sent for me. He
had learned that inventors didn't do business
by the regular process, and concluded he
would close it right up. He asked me how
much I wanted. I had made up my mind it
was certainly worth twenty-five thousand
dollars if it ever amounted to anything for
central station work; so that was the sum

164



THE TELEPHONE

I had in mind to obstinately stick to and get.
Still it had been an easy job, and only re-
quired a few months, and I felt a little shaky
and uncertain. So I asked him to make me
an offer. He promptly said he would give
me one hundred thousand dollars. * All right, '
I said, 'it is yours on one condition, and
that is that you do not pay it all at once, but
pay me at the rate of six thousand dollars a
year for seventeen years the life of the
patent. He seemed only too pleased to do
this, and it was closed. My ambition was
about four times too large for my business
capacity, and I knew that I would soon spend
this money experimenting if I got it all at
once; so I fixed it that I couldn't. I saved
seventeen years of worry by this stroke."

Edison continued his telephone work
through a number of years and made and
tested many other kinds of telephones, such
as the water telephone, electrostatic tele-
phone, condenser telephone, chemical tele-
phone, various magneto telephones, inertia
telephone, mercury telephone, voltaic pile
telephone, musical transmitter, and the electro-
motograph.

165



THE BOY'S LIFE OF EDISON

The principle of the electromotograph was
utilized by him in more ways than one; first
of all in telegraphy. Soon after the time he
had concluded the telephone arrangement
just mentioned a patent was issued to a Mr.
Page. This patent was considered very
important. It related to the use of a re-
tractile spring to withdraw the armature
lever from the magnet of a telegraph or other
relay or sounder, and thus controlled the art
of telegraphy, except in simple circuits.

" There was no known way," remarks
Edison, " whereby this patent could be evaded,
and its possessor would eventually control
the use of what is known as the relay and
sounder, and this was vital to telegraphy.
Gould was pounding the Western Union on
the Stock Exchange, disturbing its railroad
contracts, and, being advised by his lawyers
that this patent was of great value, bought it.
The moment Mr. Orton heard this he sent for
me and explained the situation, and wanted
me to go to work immediately and see if I
couldn't evade it or discover some other
means that could be used in case Gould
sustained the patent. It seemed a pretty

166



THE MOTOGRAPH

hard job, because there was no known means
of moving a lever at the other end of a tele-
graph wire except by the use of a magnet.
I said I would go at it that night. In experi-
menting some years previously I had dis-
covered a very peculiar phenomenon, and
that was that if a piece of metal connected to
a battery was rubbed over a moistened piece
of chalk resting on a metal connected to the
other pole, when the current passed the
friction was greatly diminished. When the
current was reversed the friction was greatly
increased over what it was when no current
was passing. Remembering this, I sub-
stituted a piece of chalk, rotated by a small
electric motor for the magnet, and connecting
a sounder to a metallic finger resting on the
chalk, the combination claim of Page was
made worthless. A hitherto unknown means
was introduced in the electric art. Two or
three of the devices were made and tested
by the company's expert. Mr. Orton, after
he had had me sign the patent application
and got it in the Patent Office, wanted to
settle for it at once. He asked my price.
Again I said, 'Make me an offer.' Again he

167



THE BOY'S LIFE OF EDISON

named one hundred thousand dollars. I
accepted, providing he would pay it at the rate
of six thousand dollars a year for seventeen
years. This was done, and thus, with the
telephone money, I received twelve thousand
dollars yearly for that period from the Western
Union Telegraph Company. "

A year or two later the electromotograph
principle was again made use of in a curious
manner. The telephone was being developed
in England, and Edison had made arrange-
ments with Colonel Gouraud, his old associate
in the automatic telegraph, to represent his
interests.

A company was formed, a large number of
instruments were made and sent to London,
and prospects were bright. Then there came
a threat of litigation from the owners of the
Bell patent, and Gouraud found he could not
push the enterprise unless he could avoid
using what was asserted to be an infringement
of the Bell receiver.

He cabled for help to Edison, who sent back
word telling him to hold the fort. " I had
recourse again," says Edison, "to the phe-
nomenon discovered by me some years pre-
168



THE MOTOGRAPH

vious, that the friction of a rubbing electrode
passing over a moist chalk surface was varied
by electricity. I devised a telephone receiver
which was afterward known as the 'loud-
speaking telephone/ or * chalk receiver/
There was no magnet, simply a diaphragm and
a cylinder of compressed chalk about the size
of a thimble. A thin spring connected to the
center of the diaphragm extended outwardly
and rested on the chalk cylinder, and was
pressed against it with a pressure equal to
that which would be due to a weight of about
six pounds. The chalk was rotated by hand.
The volume of sound was very great. A
person talking into the carbon transmitter in
New York had his voice so amplified that he
could be heard one thousand feet away in an
open field at Menlo Park. This great excess
of power was due to the fact that the latter
came from the person turning the handle.
The voice, instead of furnishing all the power,
as with the present receiver, merely con-
trolled the power, just as an engineer working
a valve would control a powerful engine.

"I made six of these receivers and sent
them in charge of an expert on the first

169



THE BOY'S LIFE OF EDISON

steamer. They were welcomed and tested,
and shortly afterward I shipped a hundred
more. At the same time I was ordered to
send twenty young men, after teaching them
to become expert. I set up an exchange of
ten instruments around the laboratory. I
would then go out and get each one out of
order in every conceivable way, cutting the
wires of one, short-circuiting another, destroy-
ing the adjustment of a third, putting dirt
between the electrodes of a fourth, and so on.
A man would be sent to each to find out the
trouble. When he could find the trouble ten
consecutive times, using five minutes each,
he was sent to London. About sixty men
were sifted to get twenty. Before all had
arrived, the Bell Company there, seeing we
could not be stopped, entered into negotia-
tions for consolidation. One day I received a
cable from Gouraud offering ' thirty thousand '
for my interest. I cabled back I would
accept. When the draft came I was aston-
ished to find it was for thirty thousand pounds.
I had thought it was dollars/*

After the consolidation of the Bell and
Edison interests in England the chalk receiver

170



THE MICROPHONE

was finally abandoned in favor of the Bell
receiver the latter being more simple and
cheaper. Extensive litigation with new-
comers into the telephone field followed, and
Edison's carbon transmitter patent was sus-
tained by the English courts, while Bell's was
declared invalid.

In America, the competition between the
Western Union and Bell companies, which
had been keen and strenuous, was finally
brought to an end under an agreement, the
former company agreeing to retire from the
telephonic field and the latter company agree-
ing to stay out of the telegraphic field.
Through its ownership of Edison's carbon
transmitter invention, the Western Union
company came to enjoy an annual income of
several hundred thousand dollars for some
years as a compensation for its retirement
from telephony under this agreement.

The principle involved in Edison's carbon-
transmitter gave birth to another interesting
device called the microphone, by means of
which the faintest sounds could be very
plainly heard. For instance, the footsteps
:>f a common house-fly make a loud noise

171



THE BOY'S LIFE OF EDISON

when the hearing is assisted by the micro-
phone.

The invention of this device was hotly
disputed at the time, it being claimed for
Professor Hughes, of England. Whatever
credit might be due to him for the form he
proposed, a standard history ascribes two
original forms of the microphone to Edison,
and he himself remarks: "After I sent one of
my men over to London especially to show
Preece the carbon transmitter, when Hughes
first saw it, and heard it then within a
month he came out with the microphone, with-
out any acknowledgment whatever. Pub-
lished dates will show that Hughes came along
after me."

The carbon transmitter has not been the
only way in which Edison has utilized the
peculiar property that carbon possesses of
altering its resistance to the passage of current
according to the degree of pressure brought to
bear on it.

For his quadruplex system he constructed
a rheostat, or resistance box, with a series of
silk disks saturated with plumbago and we!
dried. The pressure on the disks can



THE MICROPHONE

regulated by an adjustable screw, and in this
way the resistance of the circuit can be varied.

He also developed a "pressure," or carbon,
relay, by means of which signals of variable
strength can be transferred from one tele-
graphic circuit to another. The poles of the
electromagnet in the local or relay circuit are
hollowed out and filled up with carbon disks
or powdered plumbago.

If a weak current passes through the relay
the armature will be but feebly attracted and
will only compress the carbon slightly. Thus
the carbon will offer considerable resistance
and the signal on the local sounder will be
weak.

If, on the contrary, the incoming current
be strong, the armature will be strongly
attracted, the carbon will be more com-
pressed, thus lowering the resistance and giv-
ing a loud signal on the local sounder.

Another beautiful and ingenious use of
carbon was made by Edison in an instru-
ment invented by him called the tasimeter.
This device was used for indicating most
minute degrees of heat, and was so exceed-
ingly sensitive that in one case the heat of

173



THE BOY'S LIFE OF EDISON

rays of light from the remote star Arcturus
showed results.

The tasimeter is a very simple instrument.
A strip of hard rubber rests vertically on a
platinum plate, beneath which is a carbon
button, under which again lies another plati-
num plate. The two plates and the carbon
button form part of an electric circuit con-
taining a battery and a galvanometer. Hard
rubber is very sensitive to heat, and the
slightest rise of temperature causes it to
expand, thus increasing the pressure on the
carbon button. This produces a variation
in resistance shown by the swinging of the
galvanometer needle.

This instrument is so sensitive that with a
delicate galvanometer the heat of a person's
hand thirty feet away will throw the needle
off the scale.



XII

MAKING A MACHINE TALK

TF one had never heard a phonograph, it
* would seem as though it would be impos-
sible to take some pieces of metal and make
a machine that would repeat speaking, singing,
or instrumental music just like life.

So, before the autumn of i&iz*. when Edison
invented the phonograph, the world thought
such a thing was entirely out of the question,
[ndeed, Edison's own men in his workshop,
' who had seen him do some wonderful things,



thought the idea was absurd when 'he told
them that he was making a machine to repro-
duce human speech.

One of his men went so far as to bet him a
)ox of cigars that the thing would be an utter
failure when finished, but, as every one knows,
Edison won the bet, for the very first time the
machine was tried it repeated clearly all the
words that were spoken into it.

175






THE BOY'S LIFE OF EDISON

A story has often been told in the news-
papers that the invention was made through
Edison's ringer being pricked by a point
attached to a vibrating telephone diaphragm,
but this is not true.

The invention was not made through any
accident, but was the result of pure reasoning,
and in this case, as in many others, fact is
more wonderful than fiction. Mr. Edison's
own account of the invention of the phono-
graph is intensely interesting.

"I was experimenting," he says, "on an
automatic method of recording telegraph
messages on a disk of paper laid on a revolving i
platen, exactly the same as the disk talking- ;
machine of to-day. The platen had a spiral
groove on its surface, like the disk. Over
this was placed a circular disk of paper; an )
electro - magnet with the embossing point 1
connected to an arm traveled over the disk,| I j
and any signals given through the magnets n
were embossed on the disk of paper. If this
disk was removed from the machine and put :
on a similar machine provided with a contact
point the embossed record would cause the \
signals to be repeated into another wire. r

176



MAKING A MACHINE TALK


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Online LibraryWm. H. (William Henry) MeadowcroftThe boy's life of Edison → online text (page 8 of 15)