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THE POPULAR SCIENCE MONTHLY.

music is executed, it would be a picture of mathematical exactness, and infinite complication, that has no analogy in anything we observe. It has always been regarded as one of the mysterious miracles of vital structure how the little membranous drum of the human ear can take up so perfectly this rapid stream of intricate motions in the air, which are all so exactly reproduced by the layer of adjacent particles striking upon the membrane, that thousands of tympanums will be all affected precisely alike, while the nerves transmit the thrills to the brain, awakening the same musical sensations and sentiments in the consciousness of as many people as can be brought within hearing. This chain of effects is wonderful, indeed; but we are now confronted with the fact, more impressively than ever, that it is no prerogative of the living organism to respond to these subtile and exquisite changes in the air; the inert, dead matter of which we hear so much—mere cold iron—will do exactly the same thing.

When we begin to use a telephone for the first time, there is a sense of oddity, almost of foolishness, in the experiment. The dignity of talking consists in having a listener, and there seems a kind of absurdity in addressing a piece of iron, but we must raise our respect for the metal, for it is anything but deaf. The diaphragm of the telephone, the thin iron plate, is as sensitive as the living tympanum to all the delicate refinements of sound. Nor does it depend upon the thinness of the metallic sheet, for a piece of thick boiler-plate will take up and transmit the motions of the air-particles in all the grades of their subtilty. And not only will it do the same thing as the tympanum, but it will do vastly more: the gross, dead metal proves, in fact, to be a hundred times more alive than the living mechanism of speech and audition. This is no exaggeration. In quickness, in accuracy, and even in grasp, there is a perfection of sensitive capacity in the metal, with which the organic instrument cannot compare. We speak of the proverbial "quickness of thought," but the telephone thinks quicker than the nervous mechanism. Let a word be pronounced for a person to repeat, and the telephone will hear and speak it a hundred miles away in a tenth part of the time that the listener would need to utter it. Give a man a series of half a dozen notes to repeat, and he cannot do it accurately to save his life; but the iron plate takes them up, transmits them to another plate hundreds of miles off, which sings them forth instantaneously with absolute precision. The human machine can hear, and reproduce, in its poor way, only a single series of notes, while the iron ear of the telephone will take up whole chords and trains of music, and, sending them by lightning through the wire, its iron tongue will emit them in perfect relations of harmony. The correlations and transformations of impulse are besides much more extended in the telephone than in the living structure. The volitional mandate from the brain incites nervous discharges, expended in producing muscular contractions that impel the air across the vibrating cords, where it is thrown into waves. But in the case of the telephone, the airwaves are spent in producing mechanical vibrations of the metal; the secreate magnetic disturbances, which excite electrical action in the wire, and this again gives rise to magnetic changes that are still further converted into the tremors of the distant diaphragm, and these finally reappear as new trains of air-waves that affect the listener, while the whole intermediate series of changes is executed in a fraction of the time that is required by the nervous combinations of speech. And not only does the telephone beat the living machine out of sight in speed, accuracy, compass of results, and multiplicity of dynamical