revelled; and man must slave day in and day out to prepare food to meet the requirements of their pampered appetites.

He must struggle, too, to protect them from disease, and must care for them in time of illness as sedulously as he cares for his own kith and kin. Truly the ox is keeper of the man, and the seeming conquest that man has wrought has cost him dear.

But of course the story has another side. After all, Nature is not so malevolent as at first glance she seems. She has opposed man at every stage of his attempted progress; yet at the same time she has supplied him all his weapons for waging war upon her. Her great power of gravitation opposes every effort he makes; yet without that same power he could do nothing-he could not walk or stay upon the earth even; and no structure that he builds would hold in place for an instant.

So, too, the wind that smites him and tears at his handiwork, may be made to serve the purposes of turning his windmills and supplying him with power.

The water will serve a like purpose in turning his mills; and, changed to steam with the aid of Nature's store of coal, will make his steam engines and dynamos possible. Even the lightning he will harness and make subject to his will in the telegraphic currents and dynamos.

And in the fields, the grains which man struggles so arduously to produce are after all no thing of his creating. They are only adopted products of Nature, which he has striven to make serve his purpose by growing them

under artificial conditions. So, too, the domesticated beasts are creatures that belong in the wilds and in distant lands. Man has brought them, in defiance of Nature, to uncongenial climes, and made them serve as workers and as food-suppliers where Nature alone could not support them. Turn loose the cow and the horse to forage for themselves here in the inhospitable north, and they would starve. They survive because man helps them to combat the adverse conditions imposed by Nature, yet no one of them could live for an hour were not the vital capacities supplied by Nature still in control.

Everywhere, then, it is the opposing of Nature, up to certain limits, with the aid of Nature's own tools, that constitutes man's work in the world. Just in proportion as he bends the elements to meet his needs, transforms the plants and animals, defies and exceeds the limitations of primeval Nature-just in proportion as he conquers Nature, in a word, is he civilized.

Barbaric man is called a child of Nature with full reason. He must accept what Nature offers. But civilized man is the child grown to adult stature, and able in a manner to control, to dominate-if you please to conquer the parent.

If we were to seek the means by which developing man has gradually achieved this conquest, we should find it in the single word, Tools; that is to say, machines for utilizing the powers of Nature, and, as it were, multiplying them for man's benefit. So unique is the capacity that man exerts in this direction, that he has

been described as "the tool-making animal." The description is absolutely accurate; it is inclusive and exclusive. No non-human animal makes any form of implement to aid it in performing its daily work; and contrariwise every human tribe, however low its stage of savagery, makes use of more or less crude forms of implements. There must have been a time, to be sure, when there existed a man so low in intelligence that he had not put into execution the idea of making even the simplest tool. But the period when such a man existed so vastly antedates all records that it need not here concern us. For the purpose of classifying all existing men, and all the tribes of men of which history and pre-historic archæology give us any record, the definition of man as the tool-making animal is accurate and sufficient.

At first thought it might seem that an equally comprehensive definition might describe man as the working animal. But a moment's consideration shows the fallacy of such a suggestion. Man is, to be sure, the animal that works effectively, thanks to the implements with which he has learned to provide himself; but he shares with all animate creatures the task of laboring for his daily necessities. This is indeed a work-a-day world, and no creature can live in it without taking its share in that perpetual conflict which bodily necessities make imperative. Most lower animals confine their work to the mere securing of food, and to the construction of rude habitations. Some, indeed, go a step farther and lay up stores of food, in chance burrows or hollow trees; a few even manufacture rela

tively artistic and highly effective receptacles, as illustrated by the honeycomb made by the bees and their allies. Again, certain animals, of which the birds are the best representatives, construct temporary structures for the purpose of rearing their young that attain a relatively high degree of artistic perfection. The Baltimore oriole weaves a cloth of vegetable fibre that is certainly a wonderful texture to be made with the aid of claws and bill alone. It may be doubted whether human hands, unaided by implements, could duplicate it. But it is crude enough compared with even the coarsest cloth which barbaric races manufacture with the aid of implements.

So it is with any comparison of animal work with the work of man, in whatever field. The crudest human endeavor is superior to the best non-human efforts; and the explanation is found always in the fact that the ingenuity of man has enabled him to find artificial aids that add to his power of manipulation. So large a share have these artificial aids taken in man's evolution, that it has long been customary, in studying the development of civilization, to make the use of various types of implements a test of varying stages of human progress.

SCIENCE AND CIVILIZATION

The student of primitive life assures us, basing his statements on the archæological records, that there was a time when the most advanced of mankind had no tools made of better material than chipped stone. By

common consent that time is spoken of as the Rough Stone Age.

We are told that then in the course of immeasurable centuries man learned to polish his stone implements, doubtless by rubbing them against another stone, or perhaps with the aid of sand, thus producing a new type of implement which has given its name to the Age of Smooth or Polished Stone.

Then after other long centuries came a time when man had learned to smelt the softer metals, and the new civilization which now supplanted the old, and, thanks to the new implements, advanced upon it immeasurably, is called the Age of Bronze.

At last man learned to accomplish the wonderful feat of smelting the intractable metal, iron, and in so doing produced implements harder, sharper, and cheaper than his implements of bronze; and when this crowning feat had been accomplished, the Age of Iron was ushered in.

By common consent, students of the history of the evolution of society accept these successive ages, each designated by the type of implements with which the world's work was accomplished, as representing real and definite stages of human progress, and as needing no better definition than that supplied by the different types of implements.

Could the archæologist trace the stream of human progress still farther back toward its source, he would find doubtless that there were several great epochal inventions preceding the time of the Rough Stone Age, each of which was in its way as definitive and as