the Bell system in its infancy and had led the fight against the rival
companies until it was thoroughly established. Now he was directing
his genius and executive ability to so improving the telephone that
it should serve every need of communication. While the engineers
discussed theories Vail began actual tests. A trench five miles long
was dug beside a railway track by the simple expedient of hitching a
plow to a locomotive. In this trench were laid a number of wires, each
with a different covering. The gutta-percha and the rubber coverings
which had been used in cable construction predominated. It was found
that these wires would carry the telephone currents, not as well as
might be desired, but well enough to assure Vail that he was on the
right track. The companies began to place their wires underground, and
Vail saw to it that the experiments with coverings for telephone wires
were continued. The result was the successful underground cables in
use to-day.
At the same time Vail and his engineers were seeking to improve the
wires themselves. Iron and steel wires had been used, but they proved
unsatisfactory, as they rusted and were poor conductors. Copper was
an excellent conductor, but the metal in the pure state is soft and
no one then knew how to make a copper wire that would sustain its own
weight. But Vail kept his men at the problem and the hard-drawn copper
wire was at length evolved. This proved just what was needed for the
telephone circuits. The copper wire was four times as expensive as the
iron, but as it was four times as good Vail adopted it.
John Carty had rather more than kept pace with these improvements. He
was but twenty-six years of age when Union N. Bethell, head of the New
York company, picked Carty to take charge of the telephone engineering
work in the metropolis. Bethell was Vail's chief executive officer,
and under him Carty received an invaluable training in executive work.
Carty's largest task was putting the wires underground, and here again
he was a tremendous success. He found ways to make cables cheaper
and better, and devised means of laying them at half the former cost.
Having solved the most pressing problems in this field, his employers,
who had come to recognize his marked genius, set him to work again on
the switchboard. He was placed in charge of the switchboard department
of the Western Electric Company, the concern which manufactures the
apparatus for the telephone company. The switchboard, as we have
seen, was Carty's first love, and again he pointed the way to great
improvements. Most of the large switchboards of that time were
installed under his direction, and they were better switchboards than
had ever been known before.
Up to this time it had been thought necessary to have individual
batteries supplying current to each line. These were a constant source
of difficulty, and Carty directed his own attention, and that of his
associate engineers, to finding a satisfactory solution. He sought a
method of utilizing one common battery at the central station and the
way was found and the improvement accomplished.
Though the telephone circuits were now protected from the earth,
telephone-users, at times when the lines were busy, were still
troubled with roarings and strange cross-talk. Though busy with the
many engineering problems which the telephone heads had assigned to
him, Carty found time for some original research. He showed that the
roarings in the wires were largely caused by electro-static induction.
In 1889 he read a paper before the Electric Club that startled the
engineers of that day. He demonstrated that in every telephone circuit
there is a particular point at which, if a telephone is inserted, no
cross-talk can be heard. He had worked out the rules for determining
this point. Thus he had at once discovered the trouble and prescribed
the cure. Of course it could not be expected that the sage experts
would all agree with young Carty right away; but they were forced to
in the end, for again he was proved right.
By 1901 Carty was ready with another invention which was to place the
telephone in the homes of hundreds of thousands who, without it, could
scarcely have afforded this modern necessity. This was the "bridging
bell" which made possible the party line. By its use four telephones
could be placed on a single line, each with its own signal, so that
any one could be rung without ringing the others. Its introduction
inaugurated a new boom in the use of the telephone.
Theodore Vail had resigned from his positions with the telephone
companies in 1890 with the determination to retire from business. But
when the panic of 1907 came the directors of the company went to him
on his Vermont farm and pleaded with him to return and again resume
the leadership. Other and younger men would not do in this business
crisis. They also pointed out that the nation's telephones had not
yet been molded into the national system which had been his dream--a
system of universal service in which any one at any point in the
country might talk by telephone with any other. So Vail re-entered
the telephone field and again took the presidency of the American
Telephone and Telegraph Company.
One of his first official acts was to appoint John J. Carty his chief
engineer. Vail had selected the right man to make his dreams come
true; Carty now had the executive who would make it possible for
him to accomplish even larger things. He set about building up the
engineering organization which was to accomplish the work, selecting
the most brilliant graduates of American technical schools. He set
this organization to work upon the extension and development of the
long-distance telephone lines.
As a "hello boy" Carty had believed in the possibility of the
long-distance telephone when others had scoffed. He has told of an
early experience while in the Boston exchange:
One hot day an old lady toiled up the inevitable flights of
stairs which led to the telephone-office of those times.
Out of breath, she sat down, and when she had recovered
sufficiently to speak she said she wanted to talk to Chicago.
My colleagues of that time were all what the ethnologists
would rank a little bit lower than the wild Indian. These
youngsters set up a great laugh; and, indeed, the absurdity of
the old lady's project could hardly be overstated, because
at that time Salem was a long-distance line, Lowell sometimes
worked, and Worcester was the limit--that is, in every sense
of the word. The Lowell line was so unreliable that we had a
telegraph operator there, and when the talk was not possible,
he pushed the message through by Morse. It is no wonder that
the absurdity of the old lady's proposal was the cause
of poorly suppressed merriment. But I can remember that I
explained to her that our wires had not yet been extended to
Chicago, and that, after she had departed, I turned to the
other operators and said that the day would come when we could
talk to Chicago. My prophecy was received with what might
be called--putting it mildly--vociferous discourtesy.
Nevertheless, I remember very well the impression which that
old lady's request made upon me; and I really did believe
that, some day or other, in some way, we would be able to talk
to Chicago.
By 1912 it was possible to talk from New York to Denver, a distance of
2,100 miles. No European engineers had achieved any such results, and
this feat brought to Carty and his wonderful staff the admiration
of foreign experts. But for the American engineers this was only a
starting-point.
The next step was to link New York and California. This was more than
a matter of setting poles and stringing wires, stupendous though this
task was. The line crosses thirteen States, and is carried on 130,000
poles. Three thousand tons of wire are used in the line. The Panama
Canal took nine years to complete, and cost over three hundred million
dollars; but within that time the telephone company spent twice that
amount in engineering construction work alone, extending the scope of
the telephone.
The technical problems were even more difficult. Carty and his
engineers had to find a way to send something three thousand
miles with the breath as its motive power. It was a problem of the
conservation of the tiny electric current which carried the speech.
The power could not be augmented or speech would not result at the
destination.
Added to the efforts of these able engineers was the work of Prof.
Michael I. Pupin, of Columbia University, whose brilliant invention
of the loading coil some ten years before had startled the scientific
world and had increased the range of telephonic transmission through
underground cables and through overhead wires far beyond what
had formerly been possible. Professor Pupin applied his masterful
knowledge of physics and his profound mathematical attainments
so successfully to the practical problems of the transmission of
telephone speech that he has been called "the telephone scientist."
It is impossible to talk over long-distance lines anywhere in America
without speaking through Pupin coils, which are distributed throughout
the hundreds of thousands of miles of wire covering the North American
continent. In the transcontinental telephone line Pupin coils play a
most important part, and they are distributed at eight-mile intervals
throughout its entire length from the Atlantic to the Pacific. In
speaking at a dinner of eminent scientists, Mr. Carty once said that
on account of his distinguished scientific attainments and wonderful
telephonic inventions, Professor Pupin would rank in history alongside
of Bell himself.
We have seen how Alexander Graham Bell, standing in the little room in
Boston, spoke through the crude telephone he had constructed the first
words ever carried over a wire, and how these words were heard and
understood by his associate, Thomas Watson. This was in 1876, and it
was in January of 1915--less than forty years later--that these
two men talked across the continent. The transcontinental line was
complete. Bell in the offices of the company in New York talked freely
with Watson in San Francisco, and all in the most conversational
tone, without a trace of the difficulty that had attended their first
conversation over the short line. Thus, within the span of a single
life the telephone had been developed from a crude instrument which
transmitted speech with difficulty over a wire a hundred feet long,
until one could be heard perfectly, though over three thousand miles
of wire intervened.
The spoken word travels across the continent almost instantaneously,
far faster than the speed of sound. If it were possible for one to be
heard in San Francisco as he shouted from New York through the air,
four hours would be required before the sound would arrive. Thus the
telephone has been brought to a point of perfection where it carries
sound by electricity and reproduces it again far more rapidly and
efficiently than sound can be transmitted through its natural medium.
XX
TELEPHONING THROUGH SPACE
The Search for the Wireless Telephone--Early Successes--Carty and
His Assistants Seek the Wireless Telephone--The Task Before Them--De
Forest's Amplifier--Experimental Success Achieved--The
Test--Honolulu and Paris Hear Arlington--The Future.
No sooner had Marconi placed the wireless telegraph at the service of
the world than men of science of all nations began the search for
the wireless telephone. But the vibrations necessary to reproduce the
sound of the human voice are so infinitely more complex than those
which will suffice to carry signals representing the dots and
dashes of the telegraph code that the problem long defied solution.
Scientists attacked the problem with vigor, and various means of
wireless telephony were developed, without any being produced which
were effective over sufficient ranges to make them really useful.
Probably the earliest medium chosen to carry wireless speech was light
rays. A microphone transmitter was arranged so that the vibrations
of the voice would affect the stream of gas flowing in a sensitive
burner. The flame was thus thrown into vibrations corresponding to the
vibrations of sound. The rays from this flame were then directed by
mirrors to a distant receiving station and there concentrated on
a photo-electric selenium cell, which has the strange property of
varying its resistance according to the illumination. Thus a telephone
receiver arranged in series with it was made to reproduce the sounds.
This strange, wireless telephone was so arranged that a search-light
beam could be used for the light path, and distances up to three miles
were covered. Even with this limited range the search-light telephone
had certain advantages. Its message could be received only by those in
the direct line of the light. Neither did it require aerial masts
or wires and a trained telegrapher who could send and receive the
telegraph code. It was put to some use between battle-ships and
smaller craft lying within a radius of a few miles. The sensitive
selenium cell proved unreliable, however, and this means of
communication was destined to failure.
The experimenters realized that future success lay in making the ether
carry telephonic currents as it carried telegraphic currents. They
succeeded in establishing communication without wires, using the same
antenna as in wireless telegraphy, and the principles determined are
those used in the wireless telephone of to-day. The sending apparatus
was so arranged that continuous oscillations are set up in the ether,
either by a high-frequency machine or from an electric arc. Where
set up by spark discharges the spark frequency must be above twenty
thousand per second. This unbroken wave train does not affect the
telephone and is not audible in a telephone receiver inserted in the
radio receiving circuit. But when a microphone transmitter is inserted
in the sending circuit, instead of the make-and-break key used for
telegraphy, the waves of the voice, thrown against the transmitter
in speaking, break up the waves so that the telephone receiver in the
receiving circuit will reproduce sound. Here was and is the wireless
telephone. Marconi and many other scientists were able to operate
it successfully over comparatively short distances, and were busily
engaged in extending its range and improving the apparatus. One
great difficulty involved was in increasing the power of the sending
apparatus. Greater range has been secured in wireless telegraphy by
using stronger sending currents. But the delicate microphone would
not carry these stronger currents. Increased sensitiveness in the
receiving apparatus was also necessary.
Not content with their accomplishments in increasing the scope of the
wire telephone, the engineers of the Bell organization, headed by
John J. Carty, turned their attention to the wireless transmission
of speech. Determined that the existing telephone system should be
extended and supplemented in every useful way, they attacked the
problem with vigor. It was a problem that had long baffled the keenest
of European scientists, including Marconi himself, but that did not
deter Carty and his associates. They were determined that the glory of
spanning the Atlantic by wireless telephone should come to America
and American engineers. They wanted history to record the wireless
telephone as an American achievement along with the telegraph and the
telephone.
The methods used in achieving the wireless telephone were widely
different from those which brought forth the telegraph and the
telephone. Times had changed. Men had found that it was more effective
to work together through organizations than to struggle along as
individuals. The very physical scope of the undertakings made the old
methods impracticable. One cannot perfect a transcontinental telephone
line nor a transatlantic wireless telephone in a garret. And with a
powerful organization behind them it was not necessary for Carty
and his associates to starve and skimp through interminable years,
handicapped by the inadequate equipment, while they slowly achieved
results. This great organization, working with modern methods,
produced the most wonderful results with startling rapidity.
Important work had already been done by Marconi, Fessenden, De Forest,
and others. But their results were still incomplete; they could not
talk for any considerable distance. Carty organized his staff with
care, Bancroft Gerhardi, Doctor Jewett, H.D. Arnold, and Colpitts
being prominent among the group of brilliant American scientists
who joined with Carty in his great undertaking. While much had
been accomplished, much still remained to be done, and the various
contributions had to be co-ordinated into a unified, workable whole.
In large part it was Carty's task to direct the work of this staff and
to see that all moved smoothly and in the right direction. Just as
the telephone was more complex than the telegraph, and the wireless
telegraph than the telephone, so the apparatus used in wireless
telephony is even more complex and technical. Working with the
intricate mechanisms and delicate apparatus, one part after another
was improved and adapted to the task at hand.
To the devices of Carty and his associates was added the extremely
delicate detector that was needed. This was the invention of Dr.
Lee de Forest, an American inventor and a graduate of the Sheffield
Technical School of Yale University. De Forest's contribution was
a lamp instrument, a three-step audion amplifier. This is to the
wireless telephone what the coherer is to the wireless telegraph. It
is so delicate that the faintest currents coming through the ether
will stimulate it and serve to set in motion local sources of
electrical energy so that the waves received are magnified to a point
where they will produce sound.
By the spring of 1915, but a few months after the transcontinental
telephone line had been put in operation, Carty had his wireless
telephone apparatus ready for extended tests. A small experimental
tower was set up at Montauk Point, Long Island, and another was
borrowed at Wilmington, Delaware. The tests were successful, and the
experimenters found that they could talk freely with each other. Soon
they talked over a thousand miles, from the tower at Montauk Point
to another at St. Simon's Island, Georgia. This in itself was a great
achievement, but the world was not told of it. "Do it first and then
talk about it" is the maxim with Theodore Vail and his telephone men.
This was but a beginning, and Carty had far more wonderful things in
mind.
It was on the 29th of September, 1915, that Carty conducted the
demonstrations which thrilled the world and showed that wireless
telephony was an accomplished fact. Sitting in his office in New York,
President Theodore Vail spoke into his desk telephone of the familiar
type. The wires carried his words to the towers of the Navy wireless
station at Arlington, Virginia, where they were delivered to the
sending apparatus of the wireless telephone. Leaping into space, they
traveled in every direction through the ether. The antenna of the
wireless station at Mare Island, California, caught part of the waves
and they were amplified so that John Carty, sitting with his ear
to the receiver, could hear the voice of his chief. Carty and his
associates had not only developed a system which made it possible to
talk across the continent without wires, but they had made it possible
to combine wire and wireless telegraphy. He and Vail talked with each
other freely and easily, while the naval officers who verified the
tests marveled.
But even more wonderful things were to come. Early in the morning of
the next day other messages were sent from the Arlington tower,
and these messages were heard by Lloyd Espenschied, one of Carty's
engineers, who was stationed at the wireless station at Pearl Harbor,
near Honolulu, Hawaii. The distance covered was nearly five thousand
miles, and half of it was across land, which is the more remarkable as
the wireless does not operate so readily over land as over water.
The distance covered in this test was greater than the distance
from Washington to London, Paris, Berlin, Vienna, or Petrograd. The
successful completion of this test meant that the capitals of the
great nations of the world might communicate, might talk with
one another, by wireless telephone. Only a receiving set had been
installed at Hawaii, so that it was not possible for Espenschied to
reply to the message from Arlington, and it was not until his message
came by cable that those at Arlington knew that the words they had
spoken had traveled five thousand miles. Other receiving sets had been
located at San Diego and at Darien on the Isthmus of Panama, and at
these points also the words were distinctly heard.
By the latter part of October all was in readiness for a transatlantic
test, and on the 20th of October American engineers, with American
apparatus installed at the great French station at the Eiffel Tower,
Paris, heard the words spoken at Arlington, Virginia. Carty and his
engineers had bridged the Atlantic for the spoken word. Because of
war-time conditions it was not possible to secure the use of the
French station for an extended test, but the fact was established that
once the apparatus is in place telephonic communication between Europe
and America may he carried on regularly.
The apparatus used as developed by the engineers of the Bell system
was in a measure an outgrowth of their work with the long-distance
telephone. Wireless telephony, despite the wonders it has already
accomplished, is still in its infancy. With more perfect apparatus
and the knowledge that comes with experience we may expect that speech
will girdle the earth.
It is natural that one should wonder whether the wireless telephone is
destined to displace our present apparatus. This does not seem at all
probable. In the first place, wireless telephony is now, and probably
always will be, very expensive. Where the wire will do it is the more
economical. There are many limitations to the use of the other for
talking purposes, and it cannot be drawn upon too strongly by the man
of science. It will accomplish miracles, but must not be overtaxed.
Millions of messages going in all directions, crossing and
recrossing one another, as is done every day by wire, are probably
an impossibility by wireless telephony. Weird and little-understood
conditions of the ether, static electricity, radio disturbances, make
wireless work uncertain, and such a thing as twenty-four-hour service,
seven days in the week, can probably never be guaranteed. In radio
communication all must use a common medium, and as its use increases,
so also do the difficulties. The privacy of the wire is also lacking
with the wireless telephone.
But because a way was found to couple the wireless telephone with the
wire telephone, the new wonder has great possibilities as a supplement
to our existing system. Before so very long it may be possible for an
American business man sitting in his office to call up and converse
with a friend on a liner crossing the Atlantic. The advantages
of speaking between ship and ship as an improvement over wireless
telegraphy in time of need are obvious. A demonstration of the part
this great national telephone system would play in the country's
defense in case of attack was held in May of 1916. The Navy Department
at Washington was placed in communication with every navy-yard and
post in the United States, so that the executive officers could
instantly talk with those in charge of the posts throughout the
country. The wireless telephone was used in addition to the long
distance, and Secretary of the Navy Daniels, sitting at his desk at
Washington, talked with Captain Chandler, who was at his station on
the bridge of the U.S.S. _New Hampshire_ at Hampton Roads.