If, sweeping over in retrospect the history of the world since the time when the Egyptian and Babylonian civilizations were at their height, we attempt some such classification of the stages of progress as that which we a moment ago applied to pre-historic times, we shall be led to some rather startling conclusions. In the broadest view, it will appear that the age which ushered in the historic period continued unbroken by the advance of any great revolutionary invention throughout the long centuries of pre-Christian antiquity, and well into the so-called Middle Ages of our newer era. Then came the invention of gunpowder, or at least its introduction to the Western world—since the Chinaman here lays claim to vague centuries of precedence. Following hard upon the introduction of gunpowder, with its capacity to add to the destructive efficiency of man's most sinister form of labor, came a mechanism no less epoch-making in a far different field—the printing press.

But even these inventions, great as was their influence upon the progress of civilization, can scarcely be considered, it seems to me, as taking rank with the great epochal discoveries that gave their names to the preceding ages. Nor can any invention of the sixteenth or seventeenth century be hailed as really ushering in a new era. The invention for which that honor was reserved was a development of the eighteenth century; and did not come fully to its heritage until the early days of the nineteenth century. The invention was the application of steam to the purposes of mechanics. When this application was made, as wide a gap was crossed as that which separated the Stone Age from the Age of Metal; then the epoch in which the world was living when history begins was brought to a close, and a new era, the Age of Steam, was ushered in.

Scarcely had the world begun to adjust itself to the new conditions of the Age of Steam, when yet another power was made subservient to man's needs, and the Age of Steam was supplemented, not to say supplanted, by the Age of Electricity. Of course the new progressive movements did not necessarily imply elimination of old conditions; they imply merely the subordination of old powers to newer and better ones. Stone implements by no means ceased to have utility at once when metal implements came into vogue. Bronze long held its own against iron, and still has its utility. And iron itself finds but an added sphere of usefulness in the Age of Steam and Electricity.

All great changes are relatively slow. It is only as we look back upon them and view them in perspective that they seem cataclysmic. Gunpowder did not at once supplant the crossbow, and the cannon was long held to be inferior to the catapult. The printed book did not instantly make its way against the work of the scribe. Neither did the steam engine immediately supplant water power and the direct application of human labor. But in each case the new invention virtually rang the death knell of the old method from the hour of its inauguration, and the end was no less sure because it was delayed. And it requires no great powers of divination to foretell that in the coming age, the electric dynamo driven by water power may take the place of the steam engine. The Age of Steam may pass, with only at most a few generations of domination. And it is within the possibilities that the Age of Electricity will scarcely come into its own before it may be displaced by an Age of Radio-Activity. To press that point, however, would be to enter the field of prophecy, which is no part of my present purpose.

All that I have wished to point out is that for some thousands of years after man learned to make implements of iron, the industrial world and the human civilization that depends upon it, pursued a relatively static course, like a broad, sluggish current, with no new revolutionary discovery to impel it into new channels; and that then one revolutionary discovery succeeded another with bewildering suddenness, so that we of the early days of the twentieth century are farther removed, in an industrial way, from our forerunners of two hundred years ago, than those children of the eighteenth century were from the earliest civilization that ever developed on our globe. Indeed, this startling contrast would still hold true, were we to consider the newest era as compassing only the period of a single life. There are men living to-day who were born in that epoch when the steam engine was for the first time used to turn the wheels of factories. There are many men who can well remember the first practical application of steam to railway traffic. Hosts of men can remember when the first commercial message was transmitted by electricity along a wire. Even middle-aged men recall the first cable message that linked the old world with the new. And the application of the dynamo to the purposes of the world's work is an affair of but yesterday.

The historian of the future, casting his eye back across the long perspective of history, will find civilized man pursuing an even and unbroken course across the ages from the time of the pyramids of Egypt to about the time of the French Revolution. There will be no dearth of incident to claim his attention in the way of wars and conquests, and changing creeds, and the rise and fall of nations, each pursuing virtually the same course of growth and decay as all the others. But when he comes to the close of the eighteenth century, it will not be the social paroxysm of a nation, or the meteoric career of a Napoleon that will claim his attention so much as the introduction of that new method of utilizing the powers of Nature which found its expression in the mechanism called the steam engine.

If the name of any individual stands out as the great and memorable one of that epoch of transition, at which the static current of previous civilization changed suddenly to a Niagara-current of progress, it will be the name of the great scientific inventor, rather than that of the great military conqueror—the name of James Watt, rather than that of Napoleon.

The military conqueror had his day of surpassing glory and departed, to leave the world only a little worse than he found it. But the mechanical inventor left a heritage that was to add day by day to the wealth and happiness of humanity, supplying millions of artificial hands, and making possible such beneficent improvements as no previous age had dreamed of. Tasks that human hands had performed slowly, laboriously, and inadequately, were now to be performed swiftly, with ease, and well by the artificial hands provided with the aid of the new power. Where carts drawn by horses had toiled slowly across the land, and ships driven by the wind had drifted slowly through the waters, massive trains of cars were to hurtle to the four corners of the earth with inconceivable speed, and floating palaces were to course the waters with almost equal defiance to the limitations of time and space.

And then there came that still weirder conquest of time and space, wrought by the electric current. The moment when man first spoke with man from continent to continent in defiance of the oceans, marked the dawning of that larger day when all mankind shall constitute one brotherhood and all peoples but a single nation. Within a half century the sun of that new day has risen well above the horizon, and far sooner than even the optimist of to-day dare predict with certainty, it seems destined to reach its zenith.