The Wonder Book Of Knowledge Part 26

It is characteristic of private management that plans can be made for the future with reasonable a.s.surance that the necessary funds will not be arbitrarily withheld, or that the work of the past will not be ruthlessly cast aside.

Another factor of telephone service in America is promptness. Local connections are made in a few seconds. In the case of interurban and long-distance calls, to prevent the long waiting for a turn, which abroad sometimes is a matter of hours, the American engineer provides enough long-distance trunks, so that, except in cases of accident, customers at the busiest times of the day are connected with distant points without delay.

The First Transcontinental Line.

The opening of the first transcontinental line between New York and San Francisco on January 25, 1915, was an epoch-making event in telephone history. The line is 3,400 miles long. It crosses thirteen states; it is carried on 130,000 poles. Four hard-drawn copper wires, .165 of an inch in diameter, run side by side over the entire distance, establis.h.i.+ng two physical and one phantom circuit. The ordinary telephone connection consists of two wires technically called a telephone circuit, each wire const.i.tuting one "side" of the circuit. A phantom circuit is a circuit superimposed on two ordinary circuits by so connecting the two wires or "sides" of each ordinary circuit that they can be used as one side of the phantom circuit. In this way three practical talking circuits can be obtained from four wires. One mile of single wire used in the transcontinental line weighs 435 pounds, the weight of the wires in the entire line being 5,920,000 pounds, or 2,960 tons.

[Ill.u.s.tration: THIS PICTURE SHOWS THE DIFFICULTIES ENCOUNTERED IN HAULING POLES IN A MOUNTAINOUS SECTION ALONG THE TRANSCONTINENTAL LINE OF THE BELL SYSTEM]

In addition to the transmission wires, each circuit uses some 13,600 miles of fine hair-like insulated wire .004 of an inch in diameter in its loading coils.

It was, perhaps, little more difficult to string wires from Denver to San Francisco than from New York to Denver, but the actual construction of the line was the least of the telephone engineer's troubles. His real problem was to make the line "talk," to send something 3,000 miles with a breath as the motive power. In effect, the voyage of the voice across the continent is instantaneous; if its speed should be accurately measured, a fifteenth of a second would probably be nearly exact. In other words, a message flying across the continent on the new transcontinental line, travels, not at the rate of 1,160 feet per second, which is the old stagecoach speed of sound, but at 56,000 miles per second. If it were possible for sound to carry that far, a "h.e.l.lo"

uttered in New York and traveling through the air without the aid of wires and electricity would not reach San Francisco until four hours later. The telephone not only transmits speech, but transmits it thousands of times faster than its own natural speed.

But while the telephone is breaking speech records, it must also guarantee safe delivery of these millions of little pa.s.sengers it carries every few minutes in the way of sound waves created at the rate of 2,100 a second. There must be no jostling or crowding. These tiny waves, thousands and thousands of varying shapes, which are made by the human voice, and each as irregular and as different from the other as the waves of the sea, must not tumble over each other or get into each other's way, but must break upon the Pacific coast as they started at the Atlantic, or all the line fails and the millions of dollars spent upon it have been thrown away. And in all this line, if just one pin-point of construction is not as it should be, if there is one iota of imperfection, the miles of line are useless and the currents and waves and sounds and words do not reach the end as they should. It is such tremendous trifles, not the climbing of mountains and the bridging of chasms, that make the transcontinental line one of the wonders of the ages.

The engineer in telephony cannot increase his motive power. A breath against a metal disk changes air waves into electrical currents, and these electrical currents, millions of which are required for a single conversation, must be carried across the continent and produce the same sound waves in San Francisco as were made in New York. Here is a task so fine as to be gigantic. It was to nurse and coax this baby current of electricity 3,000 miles across the continent, under rivers and over mountains, through the blistering heat of the alkali plains and the cold of snow-capped peaks, that has taken the time and thought and labor of the brightest minds of the scientific world.

This great problem in transmission was due to the c.u.mulative effect of improvements, great and small, in telephone, transmitter, line, cable, switchboard and every other piece of apparatus and plant required for the transmission of speech.

The opening of the transcontinental telephone line has been followed by the extension of "extreme distance" transmission into all the states of the Union, by applying these new improvements to the plant of the Bell System. It is now possible to talk from points in any one state to some points in every other state of the Union, while over a very large part of the territory covered by the Bell System, it is possible for any subscriber to talk to any other subscriber, regardless of distance.

Wireless Speech Transmission.

During the year 1915 very notable development in radio-telephony, the transmission of speech without wires, was made.

On April 4th the Bell telephone engineers were successful in transmitting speech from a radio station at Montauk Point, on Long Island, to Wilmington, Del.

On the 27th of August, with the Bell apparatus, installed by permission of the Navy Department at the Arlington, Va., radio station, speech was successfully transmitted from Arlington, Va., to the Navy wireless station equipped with Bell apparatus at the Isthmus of Panama.

On September 29th speech was successfully transmitted by wire from the headquarters of the company at 15 Dey Street, New York, to the radio station at Arlington, Va., and thence by radio or wireless telephony across the continent to the radio station at Mare Island Navy Yard, Cal.

[Ill.u.s.tration: SETTING POLES ACROSS A SHALLOW LAKE IN NEVADA DURING THE CONSTRUCTION OF THE TRANSCONTINENTAL LINE OF THE BELL SYSTEM]

On the next morning, at about one o'clock, Was.h.i.+ngton time, wireless telephone communication was established between Arlington, Va., and Pearl Harbor in the Hawaiian Islands, where the Bell engineer, together with United States naval officers, distinctly heard words spoken into the apparatus at Arlington.

On October 22d, from the Arlington tower in Virginia, speech was transmitted across the Atlantic Ocean to the Eiffel Tower at Paris, where the Bell engineers, in company with French military officers, heard the words spoken at Arlington.

On the same day, when speech was being transmitted by the Bell apparatus at Arlington to the engineers and the French military officers at the Eiffel Tower in Paris, the telephone company's representative at Pearl Harbor, Hawaii, together with an officer of the United States Navy, heard the words spoken from Arlington to Paris.

[Ill.u.s.tration: BY MEANS OF THE UNIVERSAL BELL SYSTEM THE NATION MAY BE PROMPTLY ORGANIZED FOR UNITED ACTION IN ANY GREAT NATIONAL MOVEMENT]

It is believed that wireless telephony will form a most important adjunct and extension to the existing schemes of communication. By its means communication can be established between points where it is impracticable to extend wires. For many reasons wireless telephony can never take the place of wire systems, but it may be expected to supplement them in a useful manner. Wireless telephone systems are subject to serious interference from numerous conditions, atmospheric and others. For many uses the fact that anyone suitably equipped can listen in on a wireless telephone talk would be a serious limitation to its use.

The Mobilization of Communication.

Besides these radio experiments, a demonstration has been given of the availability of the Bell System and its wonderful potentiality in case of an emergency which would require quick and satisfactory intercommunication between the different departments of the government and its scattered stations and officers throughout the whole country.

From 4 P. M., May 6, to 8 A. M., May 8, 1916, the United States Navy Department and the American Telephone and Telegraph Company co-operated in a general mobilization of the forces of communication. It was a test of what could be done in a sudden military emergency, and was gratuitously undertaken by the company at the request of the Secretary of the Navy.

It was a sort of war game that brought into play the latest scientific developments of telephone and telegraph communication, by wire and by wireless, and demonstrated an efficiency that has not been attained in any other country.

For some time the officers of the United States Navy had been working together with the engineers of the Bell System in the study of wire and wireless communications, and the Navy Department had permitted the telephone engineers to use its towers for long-distance wireless telephone experiments.

So, in the latest demonstration, the land towers of the navy were utilized in connection with a wireless telephone installation on the U. S. S. "New Hamps.h.i.+re," and Captain Chandler, cruising off sh.o.r.e, talked directly with the Secretary's office in Was.h.i.+ngton.

For the time being the operating forces of the telephone company all over the country were placed at the disposal of Captain W. H. G.

Bullard, Chief of the Bureau of Communications, and General Superintendent of Plant F. A. Stevenson, of the American Telephone and Telegraph Company, was a.s.signed as his aide. While all the facilities of the Bell System were available, only about 53,000 miles of wire were necessary to connect all the navy yards and stations for telephonic and telegraphic communication.

The successful demonstration showed that in case of any trouble requiring any such service, because of the central control of the Bell System, the government could have ready-made at its immediate disposal a plant, equipment and operating staff which, for completeness and efficiency, would not be possible in any other way.

Why do They Call Them "Fiddler-Crabs"?

There is one member of the crab family for which the Latin name is _Gelasimus_, which means "laughable." He certainly is appropriately named, for he is a very queer little fellow. The male has one claw of immense size, the other being quite small. The big claw is brightly colored, and when he runs he waves it about as if he were energetically beckoning, or playing some very stirring tune on a violin; hence he is often known as a "Calling-crab" or a "Fiddler-crab."

Fiddler-crabs inhabit various parts of the world, and are usually found in large numbers on muddy or sandy flats left dry by the tide, where they may be seen hurrying over the sand or peering out of their holes, into which they immediately vanish when alarmed. The holes, which usually are about a foot deep, are made by the crab persistently digging up and carrying away little ma.s.ses of mud or sand. When he is doing this the crab presents a very funny appearance. Sc.r.a.ping up a quant.i.ty of sand into a little heap, he grasps it with three of the legs on one side and hurries away with it to some little distance. Having deposited his load, he raises his eyes, which he can do quite effectively, as they are situated at the end of very long, slender stalks, peers curiously around, and scuttles back to the hole for another load of sand.

How Far can a Powerful Searchlight Send Its Rays?

Searchlights have recently been made capable of being seen nearly a hundred miles away. Such lights are very valuable for signaling purposes in time of war, and they are also much used on wars.h.i.+ps, enabling the officers to detect the approach of an enemy in the dark and to guard against torpedo boats.

[Ill.u.s.tration: LONG RIBBONS OF LIGHT

_Photo by Brown Bros._

The giant scintillator erected on the sh.o.r.e of the bay was not the least wonderful of all the wonderful sights of the Panama-Pacific Exposition at San Francisco.]

We are all familiar with the less powerful ones which are universally used on automobiles for night driving and in a mult.i.tude of other every-day practices. The ill.u.s.tration shows a battery of powerful searchlights, the use of which furnished some very effective displays during the Panama-Pacific Exposition at San Francisco in 1915.

Searchlights are ordinarily electric arc lights of great candle-power, arranged with a parabolic reflector so that the rays are sent almost wholly in one direct line, forming a path of light which may be projected for miles.

What Started the Habit of Touching Gla.s.ses Before Drinking?

Just as athletes shake hands before the beginning of a contest today, the people who fought duels in the olden days used to pause before their fighting long enough to each drink a gla.s.s of wine furnished by their friends. In order to make sure that no attempt was made to forestall the results of the duel by poisoning the wine in either cup, they developed the habit of pouring part of the contents of each gla.s.s into the other, so that if either contestant was poisoned the other would be too.

This habit has continued up to the present time, although there is no thought given now to the danger of poison, and in the present day the ceremony of actually pouring the drink from one gla.s.s to another has been omitted, merely the motion, as if to touch the gla.s.ses, sufficing as an expression of friendliness and good will.

Touching gla.s.ses together in drinking, preparatory to a confidential talk, has come to be nicknamed "hob-n.o.bbing" because of the equipment incidental to that action years ago. A "hob" was the flat part of the open hearth where water and spirits were warmed; and the small table, at which people sat when so engaged, was called a "n.o.b."