BY THE WAY

Southland Times, Issue 21073, 3 May 1930, Page 13

BY THE WAY

THE WEB OE SPEECH

(By

Rowan.)

“What an age we are living in 1 What would our grandfathers have to say about it,” exclaimed the Prime Minister of England to the Prime Minister of Australia over the wireless telephone on Wednesday, as part of the inaugural ceremony of the establishment of this new link between England and Australia. Man’s mechanism for world-wide speech* has indeed developed through prophecy to fact, and the modern mind has become so accustomed to seeing miracles translated that already the future has become vastly conjectural with unfledged dreams. And even the unsympathetic bystander can observe the enormous strides which the telephone organism, staffed by machines, but driven by brain cells, has taken in the past few years. Two decades ago long-distance telephony was an adventure and a gamble. Nowadays it is commonplace. To its success two inventions have made chief contribution, the vacuum tube amplifier and the magnetic loading coil. Thousands of others have shared. Within one decade has come reasonable perfection of the transatlantic telephone, now extended across the Pacific. At least two great ocean liners now carry apparatus permitting telephone conversation between passengers at sea and persons on shore In Germany telephony from moving trains is an accomplished fact, so that the too-busy business man gets not even travel-time for his favourite detective stories. America’s telephone research organization, the Bell Telephone Laboratories of New York City, possess an aeroplane from which scores of people have talked by long-distance telephone to friends in all parts of the United States, even in Europe. But the submarine cable for telephony is a still more potent instrument for world-wide speech.

I To the layman it seems strange that cables have not always been used in this fashion. These underwater pathways for electricity now criss cross the world’s oceans in almost every conceivable direction. Why not simply connect the telephone wires to the shore ends of these cables and talk to anybody, just as we now talk over telephone wires in cables laid under the streets? The reason why this is impossible goes back to that same set of scientific facts which made the magnetic loading coil associated with the name of Professor Pupin so important an event in the history of land telephony. Nature has decreed that electricity should possess an inseparable twin called magnetism. No electric event happens without a corresponding magnetic event. For many of the uses of electricity this fact is enormously important. No motor would run, no dynamo would produce electric current, unless both twins were suitably hired, cared for, and set to work. These are not really electric machines; they are electro-magnetic machines. Sometimes, of course, this partnership is less desirable. In long lengths of wire, for example, the magnetic stresses which electric charges produce in the surrounding space as they pulse along through the wires, often interfere with the progress of these' charges. It is as though a man were trying to run rapidly against the wind, but with his coat held out stiffly at his sides instead of wrapped around him to make as little wind resistance as possible. When the first submarine cables were laid, electric signals could be sent over them only very slowly because of this magnetic delay to the speed with which the electric charges passed The first cable of all was ruined, indeed, because impatient engineers crowded too much electricity into it in the effort to drive the signals through it faster.

With modern cables’ the dot-dash messages of the telegraph code get through with reasonable rapidity, but that would not be true for the rapidly vibrating sounds of speech. To pronounce, for example, any vowel sound, like “ah,” requires a variety of singing. Two tones must be sung at once, like two notes struck simultaneously on the piano. The speeds at which these two tones vibrate depend upon the pitch of the speaker’s voice; higher, for a shrillvoiced woman, lower, for a deep-voiced man. But.even the lowest pitched of them must vibrate at least 100 times a second, if the vowel sound is to be recognisable when heard. One hundred distinct electric pulses per second, one for each sound pulse of the vibrating tone, is utterly beyond the speed capacity of any ordinary submarine cable, even beyond that of a few hundred miles of simple land wire strung up on poles. To better this the telephone engineers had to do one of two things. Either they had to persuade their messages to wrap their inevitable electro-magnetic coats more closely to their bodies so that they would slip through with less resistance, or else it was necessary to take away the resisting air, which, in this metaphor, symbolises the retarding effect of the magnetic properties of space. The second#expedient proved to be the more successful. This is what- the magnetic loading coil may be thought of as accomplishing. By means of the new magnetic metal called permalloy, an alloy of iron and nickel perfected and invented at the Bell Telephone Laboratories; the device of magnetic loading may be applied all along the line of a cable, not merely at certain selected points where ordinary loading coils are affixed. Submarine cables thus loaded with permalloy so that the rapid vibrations of speech sounds get through them quickly enough for practical purposes, are now carrying speech between Cuba and the United States, as well as elsewhere, and it is predicted that a submarine speech cable across the Atlantic will be available before many more years. ,

At first thought such cables may seem unnecessary to the realization of worldwide speech. Transatlantic telephony is already available by radio, and now it has become transpacific as well. Why add another method? The reason is that radio possesses certain unalterable disadvantages For one thing, it takes too much ether; for but one telephone conversation can be maintained at a time over one radio “channel,” and the number of these channels, if mutual interference is to be avoided, is strictly limited. Another thing is nature’s radio, called “static,” originating from the thousand or more thunderstorms which weather experts compute to be continually in progress somewhere in the world at any given moment. Each of these storms represents a good-sized broadcasting station, and not even a cosmic SOS could persuade these lightning broadcasters to shut down. One result is that radio telephony is never so quiet and peaceful as it ought to be; nor can it ever be cheap, nor continuous regardless of storms and sunsets, nor simultaneously world-wide. Most historians have agreed that racial isolation has been a powerful force in world history. The promised world-wide spiderweb of telephone cables will stimulate human solidarity, and by the time this has been achieved one language, out of the 600 different languages now spoken by at least a modicum of people somewhere on earth, will have survived, or will at least form the basis of the world-wide speech. Perhaps the time is hardly ripe for con-

jecture as to where this commerce in speech is leading us, and, after all, it would appear that what we have to say about it matters not at all.