The history of the invention of the telephone is easily apprehended.

The scientific principles on which it depends may be understood without difficulty. There is, however, about the instrument and its action something that is well nigh unbelievable. It is essentially a thing contrary to universal experience, if not positively inconceivable, that the slight phenomenon of the human voice should be, so to speak, _picked up_ by a physical contrivance, carried a thousand miles through a thread of wire not a quarter of an inch in diameter, and delivered in its integrity to the sense of another waiting to receive it! At all events, the history of the telephone, belonging so distinctly to our own age, will stand as a reminder to after times of the great stride which the human race made in inventive skill and scientific progress in the last quarter of the nineteenth century.

The telephone, like many similar instruments, was the work of several ingenious minds directed at nearly the same time to the same problem.

The solution, however, must be accredited first of all to Elisha P.

Gray, of Chicago, and Alexander Graham Bell, of the Ma.s.sachusetts Inst.i.tute of Technology. It should be mentioned, however, that Amos E.

Dolbear, of Tufts College, Ma.s.sachusetts, and Thomas A. Edison, of Menlo Park, New Jersey, likewise succeeded in solving the difficulty in the way of telephonic communication, and in answering practically several of the minor questions that hindered at first the complete success of the invention. The telephone is an instrument for the reproduction of sounds, particularly the sounds of the human voice, by the agency of electrical conduction at long distances from the origin of the vocal disturbance. Or it may be defined as an instrument for the _transmission_ of the sounds referred to by the agencies described. Indeed it were hard to say whether in a telephonic message we receive a _reproduced_ sound or a _transmitted_ sound. On the whole, it is more proper to speak of a reproduction of the original sound by transmission of the waves in which that sound is first written.

It is now well known that the phenomenon called sound consists of a wave agitation communicated through the particles of some medium to the organ of hearing. Every particular sound has its own physical equivalent in the system of waves in which it is written. The only thing, therefore, that is necessary in order to carry a sound in its integrity to any distance, is to transmit its physical equivalent, and to redeliver that equivalent to some organ of hearing capable of receiving it.

Upon these principles the telephone was produced--created. Every sound which falls by impact upon the sheet-iron disk of the instrument communicates thereto a sort of tremor. This tremor causes the disk to approach and recede from the magnetic pole placed just behind the diaphragm. A current of electricity is thus induced, pulsates along the wire to the other end, and is delivered to the metallic disk of the second instrument, many miles away, just as it was produced in the first. The ear of the hearer receives from the second instrument the exact physical equivalent of the sound, or sounds, which were delivered against the disk of the first instrument, and thus the utterance is received at a distance just as it was given forth.

As already said, the invention of the telephone stands chiefly to the credit of Professors Gray and Bell. It should be recorded that as early as 1837, the philosopher Page succeeded, by means of electro-magnetism, in transmitting _musical_ tones to a distance. It was not, however, until 1877 that Professer Bell, in a public lecture given at Salem, Ma.s.s., astonished his audience, and the whole country as well, by receiving and transmitting _vocal_ messages from Boston, twenty miles away. Incredulity had no more a place as it respected the feasibility of talking to persons at a distance. The experiments of Gray at Chicago, a few days later in the same month, were equally successful. Messages were distinctly delivered between that city and Milwaukee, a distance of eighty-five miles, nor could it be longer doubted that a new era in the means of communication had come.

The Bell telephone, with its many modifications and improvements, has come into rapid use. Within reasonable limits of distance, the new method of transmitting intelligence by direct vocal utterance, has taken the place of all slower and less convenient means of intercommunication. The appearance of the simple instrument has been one of the many harbingers of the oncoming better time, when the interchange of thought and sentiment between man and man, community and community, nation and nation, and race and race shall be the preliminary of universal peace in the world and of the good-fellowship of mankind.

Every such fact as the invention of the telephone, produces a complex and almost indescribable result in human society. This result has in it, in the first place, a change in the manners and method of the individual There is also a change in his sentiments. He whose work in life, whatever it may be, is accomplished in touch with the telephone will realize that he is in touch with the whole world. This intimacy reaches, first, his neighbors and friends. He seems to live henceforth in their presence, and in communication with them.

The isolation of the individual life is virtually obliterated by such an agency. Solitude disappears before it; for he whose ear is within hearing of his instrument, knows not at what moment any one of many thousands of people may speak to him. He knows not at what moment intelligence of an ever-varying kind may be spoken to him from his own community or out of the depths of distance. The mind is thus affiliated with an enlarged and ever-present society. These considerations do not relate to mere matters of convenience and quickness and advantage and safety, but to the larger question of the aggregate effect upon the individual.

The effect on the community is of like kind. The community is no longer so segregated as it was before. The community is in touch with other communities of like character. The conflagration in one town is felt in the neighboring towns, if it is not seen. The epidemic of the one is the epidemic of many. The sensation of the one community diffuses itself instantly into several. The effect is in the intellectual life like that of a wave produced on the lake by the casting in of a stone. The wave widens and recedes. It may be obstructed or un.o.bstructed in its progress. If obstructed, the obstructions may be removed. Then the motion of the wave will become free and regular. So also on the tide of public thought. The telephone is an agency _for removing mental obstructions_, and for the regular diffusion of a common thought.

All this, however, is attended with draw-backs. One of these is the breaking in on the privacy and seclusion of the individual life.

Individuality suffers under scientific progress. Great thinking is accomplished best in solitude. Emerson has forcibly pointed out the advantages which arise in the intellectual life from its isolation and seclusion--from its free and uninterrupted communion with itself.

The convenience--the physical convenience--of life is vastly augmented by such a contrivance as the telephone. Time is saved and trouble obviated. But at the same time the necessity for bodily exercise is reduced, and the overgrowth of brain at the expense of body encouraged.

The fact is that the invention of the telephone and its general use, while it has added very greatly to the comfort of life, while it has promoted ease and diffused a social sense that needed stimulation and development, has at the same time brought in conditions that are not wholly favorable to human welfare. More largely still, the truth is that the telephone, like every other symbol and agency of progress, has brought _enlarged responsibilities._

No man, no community, no people or nation can gain an increase of power without accepting the accompanying increase of responsibility.

The moral nature of man is thus involved. Every forward stride of scientific invention places upon the life of man, including his bodily activity, his mental moods and his spiritual and moral powers, an added stress of duty, of energy, and of rect.i.tude in conduct from which he may not shrink if he would be the gainer rather than the loser. Each discovery and each improved method of employing the beneficent forces of the natural world, brings with it a strain upon the moral nature of man which, if he stand it, well; but if he stand it not, then it shall go ill with him.

THE MACHINE THAT "TALKS BACK."

The invention for making nature give an intelligent response may well be regarded with wondering interest. The odd, we might say humorous, feature of the invention is that nature, being as it were cornered and compelled to respond, will answer nothing except _to repeat what is said in her ear!_ The phonograph may be defined as a mechanical parrot. Unlike the living bird, however, it never makes answers malapropos. It never deviates from the original text. The distrust which has been justly cherished against the talking bird on account of his originality can never be reasonably directed against the phonograph!

The possibility of writing sound has been recognized for a century past. Since the discovery of the vibratory character of sound, the physicist has seen the feasibility of recording the vibration. Nature herself has given many hints along this line of experimentation. Long ago it was seen that the writing sand sprinkled on the sounding board of the piano would under the influence of a chord struck from the keys arrange itself in geometrical figures. It was also seen that a discord sounded from the key-board would break the figures into chaos and confusion. Were not these phenomena sufficient to suggest that sound might be written in intelligible characters?

The mind, however, moves slowly from the old to the new. The former concept of physical facts and the laws which govern them is not readily given up. A great discovery in physical science seems to disturb the foundations of nature. It does not really do so; the disturbance is not in nature, but in the mind. No endeavor of man, no advance of his from some old bivouac to a new camping-ground, affects in the least the order of the world. The change, we repeat, is in the man, and in the race to which he belongs.

Long and tedious has been the process of getting thought into a recorded form. The first method of expressing thought was oral. Long before any other method of holding ideas and delivering them to others was devised or imagined, speech came. Speech is oral. It is made of sound. Oral utterance is no doubt as old as the race itself. It began with the first coming of our kind into this sphere. Indeed we now know that the rudiments of speech exist in the faculties of the lower animals. The studies of Professor Garner have shown conclusively that the humble simian folk of the African forest have a speech or language. Of this the professor himself has become a student, and he claims to have learned at least sixty words of the vocabulary!

Strange it is to note the course which linguistic development has taken. At the first, there was a _spoken_ language only. The next stage was to get this spoken language recorded, not in _audible_, but in _visible_ symbols. Why should it have been so easy and apparently natural for the old races to invent a visible form of speech-writing rather than an audible form? Why should the ancients have fallen back on the eye rather than the ear as the sense to be instructed? Why should sight-writing have been invented thousands of years ago, and sound-writing postponed until the present day?

In any event, such has been the history of recorded language. The early races began as the mother begins with her children; that is, with oral speech. But at a certain stage this method was abandoned, and teachers came with pictorial symbols of words. They invented visible characters to signify words, syllables, sounds. Thus came alphabetical writing, syllabic writing, verbal writing, into the world. Ever afterward the children of men learned speech first from their parents, by oral utterance; but afterward by means of the pictorial signs in which human language was recorded.

This method became habitual. The eye was made to be the servant of the intellect in learning nearly all that was to be gained from the wisdom of the past. It was by the tedious way of crooked marks signifying words that ideas were henceforth gleaned out of human lore by all who would learn aught from the recorded wisdom of mankind. And yet there never was anything essentially absurd or insurmountable in the invention of a method of recording speech in audible instead of visible symbols.

The phonograph came swiftly after the telephone. The new instrument is in a sense the complement of its predecessor. Both inventions are based upon the same principle in science. The discovery that every sound has its physical equivalent in a wave or agitation which affects the particles of matter composing the material through which the sound is transmitted led almost inevitably to the other discovery of _catching_ and _retaining_ that physical equivalent or wave in the surface of some body, and to the reproduction of the original sound therefrom.

Such is the fundamental principle of the interesting but, thus far, little useful instrument known as the phonograph. The same was invented by Thomas A. Edison, of Menlo Park, in the year 1877. The instrument differs considerably in structure and purpose from the _Vibrograph_ and _Phonautograph_ which preceded it. The latter two instruments were made simply to _write_ sound vibrations; the former, to reproduce _audibly_ the sounds themselves.

The phonograph consists of three princ.i.p.al parts,--the sender or funnel-shaped tube, with its open mouth-piece standing toward the operator; the diaphragm and stylus connected therewith, which receives the sound spoken into the tube; and thirdly, the revolving cylinder, with its sheet-coating of tin-foil laid over the surface of a spiral groove to receive the indentations of the point of the stylus. The mode of operation is very simple. The cylinder is revolved; and the point of the stylus, when there is no sound agitation in the funnel or mouth-piece, makes a smooth, continuous depression in the tin-foil over the spiral groove. But when any sound is thrown into the mouth-piece the iron disk or diaphragm is agitated; this agitation is carried through the stylus and written in irregular marks, dots, and peculiar figures in the tin-foil over the groove.

When the utterance which is to be reproduced has been completed, the instrument is stopped, the stylus thrown back from the groove, and the cylinder revolved backward to the place of starting. The stylus is then returned to its place in the groove, and the cylinder is revolved forward at the same rate of rapidity as before. As the point of the stylus plays up and down in the indentations and through the figures in the tin-foil, produced by its own previous agitation, a quiver exactly equivalent to that which was produced by the utterance in the mouth-piece is thrown into the air. This agitation is of course the exact physical equivalent of the original sound, or, more properly, _is_ the sound itself. Thus it is that the phonograph is made to talk, to sing, to cry; to utter, in short, any sound sufficiently powerful to produce a perceptible tremor in the mouth-piece and diaphragm of the instrument.

Much progress has been made toward the utilization of the phonograph as a practical addition to the civilizing apparatus of our time. It may be said, indeed, that all the difficulties in the way of such a result have been removed. Mr. Edison has carried forward his work to such a degree of perfection that the instrument may be practically employed in correspondence and literary composition. The problem has been to _stereotype_, so to speak, the tin-foil record of what has been uttered in the mouth-piece, and thus to preserve in a permanent form the potency of vanished sounds. Nor does it require a great stretch of the imagination to see in the invention of the phonograph one of the greatest achievements of the age--a discovery, indeed, which may possibly revolutionize the whole method of learning.

It would seem clear that nature has intended the _ear_, rather than the eye, to be the organ of education. It is manifestly against the fitness of things that the eyes of all mankind should be strained, weakened, permanently injured in childhood, with the unnatural tasks which are imposed upon the delicate organ. It would seem to be more in accordance with the nature and capacities of man, and the general character of the external world, to reserve the eye for the discernment and appreciation of beauty, and to impose upon the ear the tedious and hard tasks of education.

The phonograph makes it possible to read by the ear instead of by the eye, and it is not beyond the range of probability that the book of the future, near or remote, will be written in phonographic plates and made to reveal its story directly to the waiting ear, rather than through the secondary medium of print to the enfeebled and tired eye of the reader.

We hardly venture on prophecy; but we think that he who returns to this scene of human activity at the close of the twentieth century will find that sound has been subst.i.tuted for sight in nearly everything that relates to recorded information, to learning, and to educational work. By that means the organ of hearing will be restored to its rightful office. Enlightenment and instruction of all kinds will be given by means of phonographic books. The sound-wave will, in a word, be subst.i.tuted for the light-wave as the vehicle of all our best information and intercourse. The ear will have habitually taken the place of the eye in the princ.i.p.al offices of interest and information.

The unnatural method of the book--the visible book instead of the audible book--will then be done away. Nature, who instructs the child by sound, will continue to teach the man in the same manner. All mothers, from the mother bird to the mother woman, begin the teaching of their offspring by sound, by utterance. The mother bird continues in this manner; but the mother woman is presently supplanted by a teacher who comes in with a printed book filled with crooked marks, and would have it that learning must be _thus_ acquired. Instead of continuing the natural process of instruction to the complete development and information of the mind, an abnormal method has been adopted by mankind with many hurtful consequences.

The youth at a certain age is led into the world of science, and there dismissed from the mother-method, to acquire, if he can, the painful and tedious use of meaningless hieroglyphics. There he must study with the eye, learning as best he may the significance of the crooked signs which can at the most signify no more than words. How much of human energy and life and thought have been thus wasted in the instruction of the mind by characters and symbols. The eyes of mankind have, as we said, been dimmed and shadowed, and at the same time the faculties have been overheated and the equipose of perception and memory seriously disturbed by this unnatural process of learning.

Human beings begin the acquirement of knowledge with words, and they end with words; but an unnatural civilization has taught man to walk the greater part of his intellectual journey by means of arbitrary systems of writing and printing. When the next Columbian Year arrives we shall see him untaught (a hard thing withal) and retaught on nature's plan of learning. Nature teaches language by sound only.

Artificiality writes a scrawl. Nature's book is a book of words. Man's book is as yet a book of signs and symbols. Nature's book utters itself to the ear, and man's book blinds the eyes and overheats the imagination. Nature's method is to teach by the ear, and to reserve the sight for the discovery and enjoyment of beauty.

The sound-book in some form is coming; and with that the intellectual repose of mankind will begin to be restored. The use of the eye for the offices of education instead of the stronger ear, has, we think, impaired, if it has not destroyed, the equilibrium of the human mind.

That equilibrium must be restored. The mental diseases and unrest of our race are largely attributable to the over-excitement of the faculties through ages of too much seeing.

The Age of Hearing is, we think, to be ushered in with the twentieth century. The coming of that age will tend to restore the mental balance of mankind. Memory, now almost obliterated, will come again.

The over-heated perceptions will cool. The imagination will become calm, and the eye itself will recover, we hope, from the injuries, of overstrain, and will regain its power and l.u.s.tre. Man will see once more as the eagle sees, and will learn Shakespeare by heart. He will remember all knowledge, and will again be able to see, as of old, from Sicily to Carthage!

THE EVOLUTION OF THE DYNAMO.

BY PROFESSOR JOSEPH P. NAYLOR, A.M.

It is difficult to estimate the influence in modifying and shaping the nineteenth century civilization that has resulted from the discovery of the dynamo and the production of heavy currents of electricity.

That it has had great influence is evident without question. The arc light for out-of-doors lighting and the incandescent lamp for inside has modified all our previous ideas of illumination. Effects in light are now produced daily that were beyond imagination twenty years since. The trolley and the electromoter have largely solved the problem of rapid transit through our crowded cities. Thus larger business facilities, suburban homes and cheaper living, cleanliness and better sanitary conditions are electrical results.

The transmission of energy by the electric current from a central plant makes possible many small industries that could not exist without it, and gives employment and happiness to hundreds. The art of Electro-metallurgy seems but the development of months: yet it already employs millions of capital and is adding thousands daily to the world's wealth. Steam and wind and tide contribute to the work. Even Niagara is being touched by the spirit of the time and sends her wasting energy thrilling through the electric wires to turn the wheels of many busy factories. It is perhaps not the least remarkable fact in connection with this work that it is largely the product of the last thirty years, and that it had its very beginning less than seventy years since. Edison and Thompson and Brush are honorable household names; yet they are still living to produce even greater electric marvels. In fact, so rapid and brilliant has been the development that in the brilliancy some of the pioneers in the work have been almost forgotten, except by the specialist and the student, and it is no small part of this sketch to do them honor. The tiny spark of Faraday may be lost in the brilliancy of the million-candle-power search-light, yet the brilliancy of the search-light but enhances the wonder of the discovery of the spark.

The discovery of electro-magnetic induction marked the beginning of a new era; for in it lay all the possibilities of the future of electrical science. Michael Faraday, the third son of a poor English blacksmith, was born at Newington, Surrey, England, September 3, 1791.

His father's health was never the best, and due to the resulting straitened circ.u.mstances his early education consisted of the merest rudiments of reading, writing and arithmetic. His early life was, no doubt, largely spent in the street; but at thirteen he became errand boy to a book-seller of London. About a year later he was apprenticed to a book binder, with whom he served seven years, learning the trade.

It was while an apprentice that Faraday began reading scientific articles on chemistry and physics in the books he was set to bind. He also tried to repeat the experiments of which he read. And more, he pondered over them long and earnestly, until he saw clearly the principles involved in them. It was in these early days of experimenting and self-education that the desire to become a philosopher was implanted in his mind. He embraced every chance for scientific study and caught every opportunity for intellectual self-improvement. In the last year of his apprenticeship he was enabled through the kindness of a customer at his master's shop, to attend a course of four lectures on chemistry, given by Sir Humphry Davy at the Royal Inst.i.tution. This marked the turning point in his life. He made careful notes of the lecture, and afterward transcribed them neatly into a book and ill.u.s.trated them with drawings of the apparatus used.

After completing his apprenticeship, Faraday began life as a journeyman bookbinder. He had, however, as he says, "no taste for trade." His love of science became a consuming desire that he sought in every way to gratify. Inspired by his longing for scientific pursuits, he sent his lecture notes to Sir Humphry Davy, with the request that if opportunity offered he would give him employment at the Royal Inst.i.tution. Davy was favorably impressed with the lecture report, and sent a kindly reply to the young philosopher. Shortly after this a vacancy did happen to occur at the Inst.i.tution, and upon the recommendation of Davy, Faraday was elected to the place. Thus, in 1813, in the humble capacity of an a.s.sistant charged with the simple duty of dusting and caring for the apparatus, Michael Faraday began the life that was destined to make him the first scientist of the world and to bring honor to the Inst.i.tution which had given him his opportunity.

There is inspiration and encouragement to be found in reading the story of Faraday's success. He has been called a genius; but his genius seems to have largely consisted in persistent industry and the habit acquired in those early days of thinking over his experiments and reading until he had a clear perception of all there was in them.

He lived in his work, and loved it. In the fifty busy years that followed his installment at the Royal Inst.i.tution he digged deep into nature's secrets, and gave the world many brilliant gems as evidence of his industry. But of all his discoveries, _electro-magnetic induction_ is the crowning masterpiece and that for which the world stands most his debtor.

The principle of conservation of energy, now so well known and universally accepted, was then but a vague guess in the minds of the more advanced in science. Faraday was among the first to accept the new doctrine, and many of his brilliant discoveries were made in his effort to prove the truth of these important generalizations. He was acquainted with Sturgeon's method of making magnets by sending a current of electricity through a wire wound around a bar of iron; and he reasoned, if electricity will make a magnet, a magnet ought to make electricity. As early as 1821 his note book contains this suggestion: "Convert magnetism into electricity." Again and again he attacked the problem; but it was not until the autumn of 1831 that his efforts to solve it were successful. Then in a series of experiments that have scarcely ever been equaled in brilliancy and originality, he gave to the world the principle on which is based the wonderful development of modern electrical science.

The principle is briefly stated. The s.p.a.ce, around a wire carrying an electric current, or in the neighborhood of a magnet, has a directive effect upon a magnetic needle, and is hence called a magnetic field.