Chapter IV: Part 4

When electricians, twenty years ago, committed energy to a wire and thus enabled it to go round a corner, they felt that they had done well. The Hertz waves sent abroad by Marconi ask no wire, as they find their way, not round a corner, but through a corner. On May 1, 1899, a party of French officers on board the _Ibis_ at Sangatte, near Calais, spoke to Wimereux by means of a Marconi apparatus, with Cape Grisnez, a lofty promontory, intervening. In ascertaining how much the earth and the sea may obstruct the waves of Hertz there is a broad and fruitful field for investigation. "It may be," says Professor John Trowbridge, "that such long electrical waves roll around the surface of such obstructions very much as waves of sound and of water would do."

It is singular how discoveries sometimes arrive abreast of each other so as to render mutual aid, or supply a pressing want almost as soon as it is felt. The coherer in its present form is actuated by waves of comparatively low frequency, which rise from zero to full height in extremely brief periods, and are separated by periods decidedly longer (Fig. 73). What is needed is a plan by which the waves may flow either continuously or so near together that they may lend themselves to attuning. Dr. Wehnelt, by an extraordinary discovery, may, in all likelihood, provide the lacking device in the form of his interrupter, which breaks an electric circuit as often as two thousand times a second. The means for this amazing performance are simplicity itself (Fig. 74). A jar, _a_, containing a solution of sulphuric acid has two electrodes immersed in it; one of them is a lead plate of large surface, _b_; the other is a small platinum wire which protrudes from a glass tube, _d_. A current passing through the cell between the two metals at _c_ is interrupted, in ordinary cases five hundred times a second, and in extreme cases four times as often, by bubbles of gas given off from the wire instant by instant.

FOOTNOTES:

[3] "History of the Wireless Telegraph," by J. J. Fahie. Edinburgh and London, William Blackwood & Sons; New York, Dodd, Mead & Co., 1899. This work is full of interesting detail, well illustrated.

[4] The value of wireless telegraphy in relation to disasters at sea was proved in a remarkable way yesterday morning. While the Channel was enveloped in a dense fog, which had lasted throughout the greater part of the night, the East Goodwin Lightship had a very narrow escape from sinking at her moorings by being run into by the steamship _R. F. Matthews_, 1,964 tons gross burden, of London, outward bound from the Thames. The East Goodwin Lightship is one of four such vessels marking the Goodwin Sands, and, curiously enough, it happens to be the one ship which has been fitted out with Signor Marconi's installation for wireless telegraphy. The vessel was moored about twelve miles to the northeast of the South Foreland Lighthouse (where there is another wireless-telegraphy installation), and she is about ten miles from the shore, being directly opposite Deal. The information regarding the collision was at once communicated by wireless telegraphy from the disabled lightship to the South Foreland Lighthouse, where Mr. Bullock, assistant to Signor Marconi, received the following message: "We have just been run into by the steamer _R. F. Matthews_ of London. Steamship is standing by us. Our bows very badly damaged." Mr. Bullock immediately forwarded this information to the Trinity House authorities at Ramsgate.--_Times_, April 29, 1899.

ELECTRICITY, WHAT ITS MASTERY MEANS: WITH A REVIEW AND A PROSPECT

GEORGE ILES

[From "Flame, Electricity and the Camera," copyright by Doubleday,
Page & Co., New York.]

With the mastery of electricity man enters upon his first real sovereignty of nature. As we hear the whirr of the dynamo or listen at the telephone, as we turn the button of an incandescent lamp or travel in an electromobile, we are partakers in a revolution more swift and profound than has ever before been enacted upon earth. Until the nineteenth century fire was justly accounted the most useful and versatile servant of man. To-day electricity is doing all that fire ever did, and doing it better, while it accomplishes uncounted tasks far beyond the reach of flame, however ingeniously applied. We may thus observe under our eyes just such an impetus to human intelligence and power as when fire was first subdued to the purposes of man, with the immense advantage that, whereas the subjugation of fire demanded ages of weary and uncertain experiment, the mastery of electricity is, for the most part, the assured work of the nineteenth century, and, in truth, very largely of its last three decades. The triumphs of the electrician are of absorbing interest in themselves, they bear a higher significance to the student of man as a creature who has gradually come to be what he is. In tracing the new horizons won by electric science and art, a beam of light falls on the long and tortuous paths by which man rose to his supremacy long before the drama of human life had been chronicled or sung.

Of the strides taken by humanity on its way to the summit of terrestrial life, there are but four worthy of mention as preparing the way for the victories of the electrician--the attainment of the upright attitude, the intentional kindling of fire, the maturing of emotional cries to articulate speech, and the invention of written symbols for speech. As we examine electricity in its fruitage we shall find that it bears the unfailing mark of every other decisive factor of human advance: its mastery is no mere addition to the resources of the race, but a multiplier of them. The case is not as when an explorer discovers a plant hitherto unknown, such as Indian corn, which takes its place beside rice and wheat as a new food, and so measures a service which ends there. Nor is it as when a prospector comes upon a new metal, such as nickel, with the sole effect of increasing the variety of materials from which a smith may fashion a hammer or a blade. Almost infinitely higher is the benefit wrought when energy in its most useful phase is, for the first time, subjected to the will of man, with dawning knowledge of its unapproachable powers. It begins at once to marry the resources of the mechanic and the chemist, the engineer and the artist, with issue attested by all its own fertility, while its rays reveal province after province undreamed of, and indeed unexisting, before its advent.

Every other primal gift of man rises to a new height at the bidding of the electrician. All the deftness and skill that have followed from the upright attitude, in its creation of the human hand, have been brought to a new edge and a broader range through electric art. Between the uses of flame and electricity have sprung up alliances which have created new wealth for the miner and the metal-worker, the manufacturer and the shipmaster, with new insights for the man of research. Articulate speech borne on electric waves makes itself heard half-way across America, and words reduced to the symbols of symbols--expressed in the perforations of a strip of paper--take flight through a telegraph wire at twenty-fold the pace of speech. Because the latest leap in knowledge and faculty has been won by the electrician, he has widened the scientific outlook vastly more than any explorer who went before. Beyond any predecessor, he began with a better equipment and a larger capital to prove the gainfulness which ever attends the exploiting a supreme agent of discovery.

As we trace a few of the unending interlacements of electrical science and art with other sciences and arts, and study their mutually stimulating effects, we shall be reminded of a series of permutations where the latest of the factors, because latest, multiplies all prior factors in an unexampled degree.[5] We shall find reason to believe that this is not merely a suggestive analogy, but really true as a tendency, not only with regard to man's gains by the conquest of electricity, but also with respect to every other signal victory which has brought him to his present pinnacle of discernment and rule. If this permutative principle in former advances lay undetected, it stands forth clearly in that latest accession to skill and interpretation which has been ushered in by Franklin and Volta, Faraday and Henry.

Although of much less moment than the triumphs of the electrician, the discovery of photography ranks second in importance among the scientific feats of the nineteenth century. The camera is an artificial eye with almost every power of the human retina, and with many that are denied to vision--however ingeniously fortified by the lens-maker. A brief outline of photographic history will show a parallel to the permutative impulse so conspicuous in the progress of electricity. At the points where the electrician and the photographer collaborate we shall note achievements such as only the loftiest primal powers may evoke.

A brief story of what electricity and its necessary precursor, fire, have done and promise to do for civilization, may have attraction in itself; so, also, may a review, though most cursory, of the work of the camera and all that led up to it: for the provinces here are as wide as art and science, and their bounds comprehend well-nigh the entirety of human exploits. And between the lines of this story we may read another--one which may tell us something of the earliest stumblings in the dawn of human faculty. When we compare man and his next of kin, we find between the two a great gulf, surely the widest betwixt any allied families in nature. Can a being of intellect, conscience, and aspiration have sprung at any time, however remote, from the same stock as the orang and the chimpanzee? Since 1859, when Darwin published his "Origin of Species," the theory of evolution has become so generally accepted that to-day it is little more assailed than the doctrine of gravitation. And yet, while the average man of intelligence bows to the formula that all which now exists has come from the simplest conceivable state of things,--a universal nebula, if you will,--in his secret soul he makes one exception--himself. That there is a great deal more assent than conviction in the world is a chiding which may come as justly from the teacher's table as from the preacher's pulpit. Now, if we but catch the meaning of man's mastery of electricity, we shall have light upon his earlier steps as a fire-kindler, and as a graver of pictures and symbols on bone and rock. As we thus recede from civilization to primeval savagery, the process of the making of man may become so clear that the arguments of Darwin shall be received with conviction, and not with silent repulse.

As we proceed to recall, one by one, the salient chapters in the history of fire, and of the arts of depiction that foreran the camera, we shall perceive a truth of high significance. We shall see that, while every new faculty has its roots deep in older powers, and while its growth may have been going on for age after age, yet its flowering may be as the event of a morning. Even as our gardens show us the century-plants, once supposed to bloom only at the end of a hundred years, so history, in the large, exhibits discoveries whose harvests are gathered only after the lapse of æons instead of years. The arts of fire were slowly elaborated until man had produced the crucible and the still, through which his labours culminated in metals purified, in acids vastly more corrosive than those of vegetation, in glass and porcelain equally resistant to flame and the electric wave. These were combined in an hour by Volta to build his cell, and in that hour began a new era for human faculty and insight.

It is commonly imagined that the progress of humanity has been at a tolerably uniform pace. Our review of that progress will show that here and there in its course have been _leaps_, as radically new forces have been brought under the dominion of man. We of the electric revolution are sharply marked off from our great-grandfathers, who looked upon the cell of Volta as a curious toy. They, in their turn, were profoundly differenced from the men of the seventeenth century, who had not learned that flame could outvie the horse as a carrier, and grind wheat better than the mill urged by the breeze. And nothing short of an abyss stretches between these men and their remote ancestors, who had not found a way to warm their frosted fingers or lengthen with lamp or candle the short, dark days of winter.

Throughout the pages of this book there will be some recital of the victories won by the fire-maker, the electrician, the photographer, and many more in the peerage of experiment and research. Underlying the sketch will appear the significant contrast betwixt accessions of minor and of supreme dignity. The finding a new wood, such as that of the yew, means better bows for the archer, stronger handles for the tool-maker; the subjugation of a universal force such as fire, or electricity, stands for the exaltation of power in every field of toil, for the creation of a new earth for the worker, new heavens for the thinker. As a corollary, we shall observe that an increasing width of gap marks off the successive stages of human progress from each other, so that its latest stride is much the longest and most decisive. And it will be further evident that, while every new faculty is of age-long derivation from older powers and ancient aptitudes, it nevertheless comes to the birth in a moment, as it were, and puts a strain of probably fatal severity on those contestants who miss the new gift by however little. We shall, therefore, find that the principle of permutation, here merely indicated, accounts in large measure for three cardinal facts in the history of man: First, his leaps forward; second, the constant accelerations in these leaps; and third, the gap in the record of the tribes which, in the illimitable past, have succumbed as forces of a new edge and sweep have become engaged in the fray.[6]

The interlacements of the arts of fire and of electricity are intimate and pervasive. While many of the uses of flame date back to the dawn of human skill, many more have become of new and higher value within the last hundred years. Fire to-day yields motive power with tenfold the economy of a hundred years ago, and motive power thus derived is the main source of modern electric currents. In metallurgy there has long been an unwitting preparation for the advent of the electrician, and here the services of fire within the nineteenth century have won triumphs upon which the later successes of electricity largely proceed. In producing alloys, and in the singular use of heat to effect its own banishment, novel and radical developments have been recorded within the past decade or two. These, also, make easier and bolder the electrician's tasks. The opening chapters of this book will, therefore, bestow a glance at the principal uses of fire as these have been revealed and applied. This glance will make clear how fire and electricity supplement each other with new and remarkable gains, while in other fields, not less important, electricity is nothing else than a supplanter of the very force which made possible its own discovery and impressment.

[Here follow chapters which outline the chief applications of flame and of electricity.]

Let us compare electricity with its precursor, fire, and we shall understand the revolution by which fire is now in so many tasks supplanted by the electric pulse which, the while, creates for itself a thousand fields denied to flame. Copper is an excellent thermal conductor, and yet it transmits heat almost infinitely more slowly than it conveys electricity. One end of a thick copper rod ten feet long may be safely held in the hand while the other end is heated to redness, yet one millionth part of this same energy, if in the form of electricity, would traverse the rod in one 100,000,000th part of a second. Compare next electricity with light, often the companion of heat. Light travels in straight lines only; electricity can go round a corner every inch for miles, and, none the worse, yield a brilliant beam at the end of its journey. Indirectly, therefore, electricity enables us to conduct either heat or light as if both were flexible pencils of rays, and subject to but the smallest tolls in their travel.

We have remarked upon such methods as those of the electric welder which summon intense heat without fire, and we have glanced at the electric lamps which shine just because combustion is impossible through their rigid exclusion of air. Then for a moment we paused to look at the plating baths which have developed themselves into a commanding rivalry with the blaze of the smelting furnace, with the flame which from time immemorial has filled the ladle of the founder and moulder. Thus methods that commenced in dismissing flame end boldly by dispossessing heat itself. But, it may be said, this usurping electricity usually finds its source, after all, in combustion under a steam-boiler. True, but mark the harnessing of Niagara, of the Lachine Rapids near Montreal, of a thousand streams elsewhere. In the near future motive power of Nature's giving is to be wasted less and less, and perforce will more and more exclude heat from the chain of transformations which issue in the locomotive's flight, in the whirl of factory and mill. Thus in some degree is allayed the fear, never well grounded, that when the coal fields of the globe are spent civilization must collapse. As the electrician hears this foreboding he recalls how much fuel is wasted in converting heat into electricity. He looks beyond either turbine or shaft turned by wind or tide, and, remembering that the metal dissolved in his battery yields at his will its full content of energy, either as heat or electricity, he asks, Why may not coal or forest tree, which are but other kinds of fuel, be made to do the same?

One of the earliest uses of light was a means of communicating intelligence, and to this day the signal lamp and the red fire of the mariner are as useful as of old. But how much wider is the field of electricity as it creates the telegraph and the telephone! In the telegraph we have all that a pencil of light could be were it as long as an equatorial girdle and as flexible as a silken thread. In the telephone for nearly two thousand miles the pulsations of the speaker's voice are not only audible, but retain their characteristic tones.

In the field of mechanics electricity is decidedly preferable to any other agent. Heat may be transformed into motive power by a suitable engine, but there its adaptability is at an end. An electric current drives not only a motor, but every machine and tool attached to the motor, the whole executing tasks of a delicacy and complication new to industrial art. On an electric railroad an identical current propels the train, directs it by telegraph, operates its signals, provides it with light and heat, while it stands ready to give constant verbal communication with any station on the line, if this be desired.

In the home electricity has equal versatility, at once promoting healthfulness, refinement and safety. Its tiny button expels the hazardous match as it lights a lamp which sends forth no baleful fumes. An electric fan brings fresh air into the house--in summer as a grateful breeze. Simple telephones, quite effective for their few yards of wire, give a better because a more flexible service than speaking-tubes. Few invalids are too feeble to whisper at the light, portable ear of metal. Sewing-machines and the more exigent apparatus of the kitchen and laundry transfer their demands from flagging human muscles to the tireless sinews of electric motors--which ask no wages when they stand unemployed. Similar motors already enjoy favour in working the elevators of tall dwellings in cities. If a householder is timid about burglars, the electrician offers him a sleepless watchman in the guise of an automatic alarm; if he has a dread of fire, let him dispose on his walls an array of thermometers that at the very inception of a blaze will strike a gong at headquarters. But these, after all, are matters of minor importance in comparison with the foundations upon which may be reared, not a new piece of mechanism, but a new science or a new art.

In the recent swift subjugation of the territory open alike to the chemist and the electrician, where each advances the quicker for the other's company, we have fresh confirmation of an old truth--that the boundary lines which mark off one field of science from another are purely artificial, are set up only for temporary convenience. The chemist has only to dig deep enough to find that the physicist and himself occupy common ground. "Delve from the surface of your sphere to its heart, and at once your radius joins every other." Even the briefest glance at electro-chemistry should pause to acknowledge its profound debt to the new theories as to the bonding of atoms to form molecules, and of the continuity between solution and electrical dissociation. However much these hypotheses may be modified as more light is shed on the geometry and the journeyings of the molecule, they have for the time being recommended themselves as finder-thoughts of golden value. These speculations of the chemist carry him back perforce to the days of his childhood. As he then joined together his black and white bricks he found that he could build cubes of widely different patterns. It was in propounding a theory of molecular architecture that Kekulé gave an impetus to a vast and growing branch of chemical industry--that of the synthetic production of dyes and allied compounds.

It was in pure research, in paths undirected to the market-place, that such theories have been thought out. Let us consider electricity as an aid to investigation conducted for its own sake. The chief physical generalization of our time, and of all time, the persistence of force, emerged to view only with the dawn of electric art. When it was observed that electricity might become heat, light, chemical action, or mechanical motion, that in turn any of these might produce electricity, it was at once indicated that all these phases of energy might differ from each other only as the movements in circles, volutes, and spirals of ordinary mechanism. The suggestion was confirmed when electrical measurers were refined to the utmost precision, and a single quantum of energy was revealed a very Proteus in its disguises, yet beneath these disguises nothing but constancy itself.

"There is that scattereth, and yet increaseth; and there is that withholdeth more than is meet, but it tendeth to poverty." Because the geometers of old patiently explored the properties of the triangle, the circle, and the ellipse, simply for pure love of truth, they laid the corner-stones for the arts of the architect, the engineer, and the navigator. In like manner it was the disinterested work of investigation conducted by Ampère, Faraday, Henry and their compeers, in ascertaining the laws of electricity which made possible the telegraph, the telephone, the dynamo, and the electric furnace. The vital relations between pure research and economic gain have at last worked themselves clear. It is perfectly plain that a man who has it in him to discover laws of matter and energy does incomparably more for his kind than if he carried his talents to the mint for conversion into coin. The voyage of a Columbus may not immediately bear as much fruit as the uncoverings of a mine prospector, but in the long run a Columbus makes possible the finding many mines which without him no prospector would ever see. Therefore let the seed-corn of knowledge be planted rather than eaten. But in choosing between one research and another it is impossible to foretell which may prove the richer in its harvests; for instance, all attempts thus far economically to oxidize carbon for the production of electricity have failed, yet in observations that at first seemed equally barren have lain the hints to which we owe the incandescent lamp and the wireless telegraph.

Perhaps the most promising field of electrical research is that of discharges at high pressures; here the leading American investigators are Professor John Trowbridge and Professor Elihu Thomson. Employing a tension estimated at one and a half millions volts, Professor Trowbridge has produced flashes of lightning six feet in length in atmospheric air; in a tube exhausted to one-seventh of atmospheric pressure the flashes extended themselves to forty feet. According to this inquirer, the familiar rending of trees by lightning is due to the intense heat developed in an instant by the electric spark; the sudden expansion of air or steam in the cavities of the wood causes an explosion. The experiments of Professor Thomson confront him with some of the seeming contradictions which ever await the explorer of new scientific territory. In the atmosphere an electrical discharge is facilitated when a metallic terminal (as a lightning rod) is shaped as a point; under oil a point is the form least favourable to discharge. In the same line of paradox it is observed that oil steadily improves in its insulating effect the higher the electrical pressure committed to its keeping; with air as an insulator the contrary is the fact. These and a goodly array of similar puzzles will, without doubt, be cleared up as students in the twentieth century pass from the twilight of anomaly to the sunshine of ascertained law.

"Before there can be applied science there must be science to apply," and it is by enabling the investigator to know nature under a fresh aspect that electricity rises to its highest office. The laboratory routine of ascertaining the conductivity, polarisability, and other electrical properties of matter is dull and exacting work, but it opens to the student new windows through which to peer at the architecture of matter. That architecture, as it rises to his view, discloses one law of structure after another; what in a first and clouded glance seemed anomaly is now resolved and reconciled; order displays itself where once anarchy alone appeared. When the investigator now needs a substance of peculiar properties he knows where to find it, or has a hint for its creation--a creation perhaps new in the history of the world. As he thinks of the wealth of qualities possessed by his store of alloys, salts, acids, alkalies, new uses for them are borne into his mind. Yet more--a new orchestration of inquiry is possible by means of the instruments created for him by the electrician, through the advances in method which these instruments effect. With a second and more intimate point of view arrives a new trigonometry of the particle, a trigonometry inconceivable in pre-electric days. Hence a surround is in progress which early in the twentieth century may go full circle, making atom and molecule as obedient to the chemist as brick and stone are to the builder now.

The laboratory investigator and the commercial exploiter of his discoveries have been by turns borrower and lender, to the great profit of both. What Leyden jar could ever be constructed of the size and revealing power of an Atlantic cable? And how many refinements of measurement, of purification of metals, of precision in manufacture, have been imposed by the colossal investments in deep-sea telegraphy alone! When a current admitted to an ocean cable, such as that between Brest and New York, can choose for its path either 3,540 miles of copper wire or a quarter of an inch of gutta-percha, there is a dangerous opportunity for escape into the sea, unless the current is of nicely adjusted strength, and the insulator has been made and laid with the best-informed skill, the most conscientious care. In the constant tests required in laying the first cables Lord Kelvin (then Professor William Thomson) felt the need for better designed and more sensitive galvanometers or current measurers. His great skill both as a mathematician and a mechanician created the existing instruments, which seem beyond improvement. They serve not only in commerce and manufacture, but in promoting the strictly scientific work of the laboratory. Now that electricity purifies copper as fire cannot, the mathematician is able to treat his problems of long-distance transmission, of traction, of machine design, with an economy and certainty impossible when his materials were not simply impure, but impure in varying and indefinite degrees. The factory and the workshop originally took their magneto-machines from the experimental laboratory; they have returned them remodelled beyond recognition as dynamos and motors of almost ideal effectiveness.

A galvanometer actuated by a thermo-electric pile furnishes much the most sensitive means of detecting changes of temperature; hence electricity enables the physicist to study the phenomena of heat with new ease and precision. It was thus that Professor Tyndall conducted the classical researches set forth in his "Heat as a Mode of Motion," ascertaining the singular power to absorb terrestrial heat which makes the aqueous vapours of the atmosphere act as an indispensable blanket to the earth.

And how vastly has electricity, whether in the workshop or laboratory, enlarged our conceptions of the forces that thrill space, of the substances, seemingly so simple, that surround us--substances that propound questions of structure and behaviour that silence the acutest investigator. "You ask me," said a great physicist, "if I have a theory of the _universe_? Why, I haven't even a theory of _magnetism_!"

The conventional phrase "conducting a current" is now understood to be mere figure of speech; it is thought that a wire does little else than give direction to electric energy. Pulsations of high tension have been proved to be mainly superficial in their journeys, so that they are best conveyed (or convoyed) by conductors of tubular form. And what is it that moves when we speak of conduction? It seems to be now the molecule of atomic chemistry, and anon the same ether that undulates with light or radiant heat. Indeed, the conquest of electricity means so much because it impresses the molecule and the ether into service as its vehicles of communication. Instead of the old-time masses of metal, or bands of leather, which moved stiffly through ranges comparatively short, there is to-day employed a medium which may traverse 186,400 miles in a second, and with resistances most trivial in contrast with those of mechanical friction.

And what is friction in the last analysis but the production of motion in undesired forms, the allowing valuable energy to do useless work? In that amazing case of long distance transmission, common sunshine, a solar beam arrives at the earth from the sun not one whit the weaker for its excursion of 92,000,000 miles. It is highly probable that we are surrounded by similar cases of the total absence of friction in the phenomena of both physics and chemistry, and that art will come nearer and nearer to nature in this immunity is assured when we see how many steps in that direction have already been taken by the electrical engineer. In a preceding page a brief account was given of the theory that gases and vapours are in ceaseless motion. This motion suffers no abatement from friction, and hence we may infer that the molecules concerned are perfectly elastic. The opinion is gaining ground among physicists that all the properties of matter, transparency, chemical combinability, and the rest, are due to immanent motion in particular orbits, with diverse velocities. If this be established, then these motions also suffer no friction, and go on without resistance forever.

As the investigators in the vanguard of science discuss the constitution of matter, and weave hypotheses more or less fruitful as to the interplay of its forces, there is a growing faith that the day is at hand when the tie between electricity and gravitation will be unveiled--when the reason why matter has weight will cease to puzzle the thinker. Who can tell what relief of man's estate may be bound up with the ability to transform any phase of energy into any other without the circuitous methods and serious losses of to-day! In the sphere of economic progress one of the supreme advances was due to the invention of money, the providing a medium for which any salable thing may be exchanged, with which any purchasable thing may be bought. As soon as a shell, or a hide, or a bit of metal was recognized as having universal convertibility, all the delays and discounts of barter were at an end. In the world of physics and chemistry the corresponding medium is electricity; let it be produced as readily as it produces other modes of motion, and human art will take a stride forward such as when Volta disposed his zinc and silver discs together, or when Faraday set a magnet moving around a copper wire.

For all that the electric current is not as yet produced as economically as it should be, we do wrong if we regard it as an infant force. However much new knowledge may do with electricity in the laboratory, in the factory, or in the exchange, some of its best work is already done. It is not likely ever to perform a greater feat than placing all mankind within ear-shot of each other. Were electricity unmastered there could be no democratic government of the United States. To-day the drama of national affairs is more directly in view of every American citizen than, a century ago, the public business of Delaware could be to the men of that little State. And when on the broader stage of international politics misunderstandings arise, let us note how the telegraph has modified the hard-and-fast rules of old-time diplomacy. To-day, through the columns of the press, the facts in controversy are instantly published throughout the world, and thus so speedily give rise to authoritative comment that a severe strain is put upon negotiators whose tradition it is to be both secret and slow.

Railroads, with all they mean for civilization, could not have extended themselves without the telegraph to control them. And railroads and telegraphs are the sinews and nerves of national life, the prime agencies in welding the diverse and widely separated States and Territories of the Union. A Boston merchant builds a cotton-mill in Georgia; a New York capitalist opens a copper-mine in Arizona. The telegraph which informs them day by day how their investments prosper tells idle men where they can find work, where work can seek idle men. Chicago is laid in ashes, Charleston topples in earthquake, Johnstown is whelmed in flood, and instantly a continent springs to their relief. And what benefits issue in the strictly commercial uses of the telegraph! At its click both locomotive and steamship speed to the relief of famine in any quarter of the globe. In times of plenty or of dearth the markets of the globe are merged and are brought to every man's door. Not less striking is the neighbourhood guild of science, born, too, of the telegraph. The day after Röntgen announced his X rays, physicists on every continent were repeating his experiments--were applying his discovery to the healing of the wounded and diseased. Let an anti-toxin for diphtheria, consumption, or yellow fever be proposed, and a hundred investigators the world over bend their skill to confirm or disprove, as if the suggester dwelt next door.

On a stage less dramatic, or rather not dramatic at all, electricity works equal good. Its motor freeing us from dependence on the horse is spreading our towns and cities into their adjoining country. Field and garden compete with airless streets. The sunny cottage is in active rivalry with the odious tenement-house. It is found that transportation within the gates of a metropolis has an importance second only to the means of transit which links one city with another. The engineer is at last filling the gap which too long existed between the traction of horses and that of steam. In point of speed, cleanliness, and comfort such an electric subway as that of South London leaves nothing to be desired. Throughout America electric roads, at first suburban, are now fast joining town to town and city to city, while, as auxiliaries to steam railroads, they place sparsely settled communities in the arterial current of the world, and build up a ready market for the dairyman and the fruit-grower. In its saving of what Mr. Oscar T. Crosby has called "man-hours" the third-rail system is beginning to oust steam as a motive power from trunk-lines. Already shrewd railroad managers are granting partnerships to the electricians who might otherwise encroach upon their dividends. A service at first restricted to passengers has now extended itself to the carriage of letters and parcels, and begins to reach out for common freight. We may soon see the farmer's cry for good roads satisfied by good electric lines that will take his crops to market much more cheaply and quickly than horses and macadam ever did. In cities, electromobile cabs and vans steadily increase in numbers, furthering the quiet and cleanliness introduced by the trolley car.

A word has been said about the blessings which electricity promises to country folk, yet greater are the boons it stands ready to bestow in the hives of population. Until a few decades ago the water-supply of cities was a matter not of municipal but of individual enterprise; water was drawn in large part from wells here and there, from lines of piping laid in favoured localities, and always insufficient. Many an epidemic of typhoid fever was due to the contamination of a spring by a cesspool a few yards away. To-day a supply such as that of New York is abundant and cheap because it enters every house. Let a centralized electrical service enjoy a like privilege, and it will offer a current which is heat, light, chemical energy, or motive power, and all at a wage lower than that of any other servant. Unwittingly, then, the electrical engineer is a political reformer of high degree, for he puts a new premium upon ability and justice at the City Hall. His sole condition is that electricity shall be under control at once competent and honest. Let us hope that his plea, joined to others as weighty, may quicken the spirit of civic righteousness so that some of the richest fruits ever borne in the garden of science and art may not be proffered in vain. Flame, the old-time servant, is individual; electricity, its successor and heir, is collective. Flame sits upon the hearth and draws a family together; electricity, welling from a public source, may bind into a unit all the families of a vast city, because it makes the benefit of each the interest of all.

But not every promise brought forward in the name of the electrician has his assent or sanction. So much has been done by electricity, and so much more is plainly feasible, that a reflection of its triumphs has gilded many a baseless dream. One of these is that the cheap electric motor, by supply power at home, will break up the factory system, and bring back the domestic manufacturing of old days. But if this power cost nothing at all the gift would leave the factory unassailed; for we must remember that power is being steadily reduced in cost from year to year, so that in many industries it has but a minor place among the expenses of production. The strength and profit of the factory system lie in its assembling a wide variety of machines, the first delivering its product to the second for another step toward completion, and so on until a finished article is sent to the ware-room. It is this minute subdivision of labour, together with the saving and efficiency that inure to a business conducted on an immense scale under a single manager, that bids us believe that the factory has come to stay. To be sure, a weaver, a potter, or a lens-grinder of peculiar skill may thrive at his loom or wheel at home; but such a man is far from typical in modern manufacture. Besides, it is very questionable whether the lamentations over the home industries of the past do not ignore evil concomitants such as still linger in the home industries of the present--those of the sweater's den, for example.

This rapid survey of what electricity has done and may yet do--futile expectation dismissed--has shown it the creator of a thousand material resources, the perfector of that communication of things, of power, of thought, which in every prior stage of advancement has marked the successive lifts of humanity. It was much when the savage loaded a pack upon a horse or an ox instead of upon his own back; it was yet more when he could make a beacon-flare give news or warning to a whole country-side, instead of being limited to the messages which might be read in his waving hands. All that the modern engineer was able to do with steam for locomotion is raised to a higher plane by the advent of his new power, while the long-distance transmission of electrical energy is contracting the dimensions of the planet to a scale upon which its cataracts in the wilderness drive the spindles and looms of the factory town, or illuminate the thoroughfares of cities. Beyond and above all such services as these, electricity is the corner-stone of physical generalization, a revealer of truths impenetrable by any other ray.

The subjugation of fire has done much in giving man a new independence of nature, a mighty armoury against evil. In curtailing the most arduous and brutalizing forms of toil, electricity, that subtler kind of fire, carries this emancipation a long step further, and, meanwhile, bestows upon the poor many a luxury which but lately was the exclusive possession of the rich. In more closely binding up the good of the bee with the welfare of the hive, it is an educator and confirmer of every social bond. In so far as it proffers new help in the war on pain and disease it strengthens the confidence of man in an Order of Right and Happiness which for so many dreary ages has been a matter rather of hope than of vision. Are we not, then, justified in holding electricity to be a multiplier of faculty and insight, a means of dignifying mind and soul, unexampled since man first kindled fire and rejoiced?

We have traced how dexterity rose to fire-making, how fire-making led to the subjugation of electricity. Much of the most telling work of fire can be better done by its great successor, while electricity performs many tasks possible only to itself. Unwitting truth there was in the simple fable of the captive who let down a spider's film, that drew up a thread, which in turn brought up a rope--and freedom. It was in 1800 on the threshold of the nineteenth century, that Volta devised the first electric battery. In a hundred years the force then liberated has vitally interwoven itself with every art and science, bearing fruit not to be imagined even by men of the stature of Watt, Lavoisier, or Humboldt. Compare this rapid march of conquest with the slow adaptation, through age after age, of fire to cooking, smelting, tempering. Yet it was partly, perhaps mainly, because the use of fire had drawn out man's intelligence and cultivated his skill that he was ready in the fulness of time so quickly to seize upon electricity and subdue it.

Electricity is as legitimately the offspring of fire as fire of the simple knack in which one savage in ten thousand was richer than his fellows. The principle of permutation, suggested in both victories, interprets not only how vast empire is won by a new weapon of prime dignity; it explains why such empires are brought under rule with ever-accelerated pace. Every talent only pioneers the way for the richer talents which are born from it.

FOOTNOTES:

[5] Permutations are the various ways in which two or more different things may be arranged in a row, all the things appearing in each row. Permutations are readily illustrated with squares or cubes of different colours, with numbers, or letters.

Permutations of two elements, 1 and 2, are (1 x 2) two; 1, 2; 2, 1; or _a_, _b_; _b_, _a_. Of three elements the permutations are (1 x 2 x 3) six; 1, 2, 3; 1, 3, 2; 2, 1, 3; 2, 3, 1; 3, 1, 2; 3, 2, 1; or _a_, _b_, _c_; _a_, _c_, _b_; _b_, _a_, _c_; _b_, _c_, _a_; _c_, _a_, _b_; _c_, _b_, _a_. Of four elements the permutations are (1 x 2 x 3 x 4) twenty-four; of five elements, one hundred and twenty, and so on. A new element or permutator multiplies by an increasing figure all the permutations it finds.

[6] Some years ago I sent an outline of this argument to Herbert Spencer, who replied: "I recognize a novelty and value in your inference that the law implies an increasing width of gap between lower and higher types as evolution advances."

COUNT RUMFORD IDENTIFIES HEAT WITH MOTION.

[Benjamin Thompson, who received the title of Count Rumford from
the Elector of Bavaria, was born in Woburn, Massachusetts, in 1753.
When thirty-one years of age he settled in Munich, where he devoted
his remarkable abilities to the public service. Twelve years
afterward he removed to England; in 1800 he founded the Royal
Institution of London, since famous as the theatre of the labours
of Davy, Faraday, Tyndall, and Dewar. He bequeathed to Harvard
University a fund to endow a professorship of the application of
science to the art of living: he instituted a prize to be awarded
by the American Academy of Sciences for the most important
discoveries and improvements relating to heat and light. In 1804 he
married the widow of the illustrious chemist Lavoisier: he died in
1814. Count Rumford on January 25, 1798, read a paper before the
Royal Society entitled "An Enquiry Concerning the Source of Heat
Which Is Excited by Friction." The experiments therein detailed
proved that heat is identical with motion, as against the notion
that heat is matter. He thus laid the corner-stone of the modern
theory that heat light, electricity, magnetism, chemical action,
and all other forms of energy are in essence motion, are
convertible into one another, and as motion are indestructible. The
following abstract of Count Rumford's paper is taken from "Heat as
a Mode of Motion," by Professor John Tyndall, published by D.
Appleton & Co., New York. This work and "The Correlation and
Conservation of Forces," edited by Dr. E. L. Youmans, published by
the same house, will serve as a capital introduction to the modern
theory that energy is motion which, however varied in its forms, is
changeless in its quantity.]

Being engaged in superintending the boring of cannon in the workshops of the military arsenal at Munich, Count Rumford was struck with the very considerable degree of heat which a brass gun acquires, in a short time, in being bored, and with the still more intense heat (much greater than that of boiling water) of the metallic chips separated from it by the borer, he proposed to himself the following questions:

"Whence comes the heat actually produced in the mechanical operations above mentioned?

"Is it furnished by the metallic chips which are separated from the metal?"

If this were the case, then the _capacity for heat_ of the parts of the metal so reduced to chips ought not only to be changed, but the change undergone by them should be sufficiently great to account for _all_ the heat produced. No such change, however, had taken place, for the chips were found to have the same capacity as slices of the same metal cut by a fine saw, where heating was avoided. Hence, it is evident, that the heat produced could not possibly have been furnished at the expense of the latent heat of the metallic chips. Rumford describes these experiments at length, and they are conclusive.

He then designed a cylinder for the express purpose of generating heat by friction, by having a blunt borer forced against its solid bottom, while the cylinder was turned around its axis by the force of horses. To measure the heat developed, a small round hole was bored in the cylinder for the purpose of introducing a small mercurial thermometer. The weight of the cylinder was 113.13 pounds avoirdupois.

The borer was a flat piece of hardened steel, 0.63 of an inch thick, four inches long, and nearly as wide as the cavity of the bore of the cylinder, namely, three and one-half inches. The area of the surface by which its end was in contact with the bottom of the bore was nearly two and one-half inches. At the beginning of the experiment the temperature of the air in the shade, and also that of the cylinder, was 60° Fahr. At the end of thirty minutes, and after the cylinder had made 960 revolutions round its axis, the temperature was found to be 130°.

Having taken away the borer, he now removed the metallic dust, or rather scaly matter, which had been detached from the bottom of the cylinder by the blunt steel borer, and found its weight to be 837 grains troy. "Is it possible," he exclaims, "that the very considerable quantity of heat produced in this experiment--a quantity which actually raised the temperature of above 113 pounds of gun-metal at least 70° of Fahrenheit's thermometer--could have been furnished by so inconsiderable a quantity of metallic dust and this merely in consequence of a _change_ in its capacity of heat?"

"But without insisting on the improbability of this supposition, we have only to recollect that from the results of actual and decisive experiments, made for the express purpose of ascertaining that fact, the capacity for heat for the metal of which great guns are cast is _not sensibly changed_ by being reduced to the form of metallic chips, and there does not seem to be any reason to think that it can be much changed, if it be changed at all, in being reduced to much smaller pieces by a borer which is less sharp."

He next surrounded his cylinder by an oblong deal-box, in such a manner that the cylinder could turn water-tight in the centre of the box, while the borer was pressed against the bottom of the cylinder. The box was filled with water until the entire cylinder was covered, and then the apparatus was set in action. The temperature of the water on commencing was 60°.

"The result of this beautiful experiment," writes Rumford, "was very striking, and the pleasure it afforded me amply repaid me for all the trouble I had had in contriving and arranging the complicated machinery used in making it. The cylinder had been in motion but a short time, when I perceived, by putting my hand into the water, and touching the outside of the cylinder, that heat was generated.

"At the end of one hour the fluid, which weighed 18.77 pounds, or two and one-half gallons, had its temperature raised forty-seven degrees, being now 107°.

"In thirty minutes more, or one hour and thirty minutes after the machinery had been set in motion, the heat of the water was 142°.

"At the end of two hours from the beginning, the temperature was 178°.

"At two hours and twenty minutes it was 200°, and at two hours and thirty minutes it _actually boiled_!"

"It would be difficult to describe the surprise and astonishment expressed in the countenances of the bystanders on seeing so large a quantity of water heated, and actually made to boil, without any fire. Though, there was nothing that could be considered very surprising in this matter, yet I acknowledge fairly that it afforded me a degree of childish pleasure which, were I ambitious of the reputation of a grave philosopher, I ought most certainly rather to hide than to discover."

He then carefully estimates the quantity of heat possessed by each portion of his apparatus at the conclusion of the experiment, and, adding all together, finds a total sufficient to raise 26.58 pounds of ice-cold water to its boiling point, or through 180° Fahrenheit. By careful calculation, he finds this heat equal to that given out by the combustion of 2,303.8 grains (equal to four and eight-tenths ounces troy) of wax.

He then determines the "_celerity_" with which the heat was generated, summing up thus: "From the results of these computations, it appears that the quantity of heat produced equably, or in a continuous stream, if I may use the expression, by the friction of the blunt steel borer against the bottom of the hollow metallic cylinder, was _greater_ than that produced in the combustion of nine _wax-candles_, each three-quarters of an inch in diameter, all burning together with clear bright flames.