"I think that will do on that point," answered the teacher. "We will now ask you to tell us something more particularly of this great period of invention which began in the latter part of the eighteenth century." HAROLD STATES THE FACTS. "From the times of antiquity up to the last quarter of the eighteenth century," said the lad, "there had been almost no progress in the mechanical sciences save as to shipbuilding and arms. From 1780, or thereabouts, dates the beginning of a series of discoveries of sources of power, and their application by machinery to economic purposes, which, during the century following, completely revolutionized the conditions of industry and commerce. Steam and coal meant a multiplication of human energy in the production of wealth which was almost incalculable. For industrial purposes it is not too much to say that they transformed man from a pygmy to a Titan. These were, of course, only the greatest factors in a countless variety of discoveries by which prodigious economies of labor were effected in every detail of the arts by which human life is maintained and ministered to. In agriculture, where Nature, which can not be too much hurried, is a large partner, and wherein, therefore, man's part is less controlling than in other industries, it might be expected that the increase of productive energy through human invention would be least. Yet here it was estimated that agricultural machinery, as most perfectly developed in America, had multiplied some fifteenfold the product of the individual worker. In most sorts of production less directly dependent upon Nature, invention during this period had multiplied the efficiency of labor in a much greater degree, ranging from fifty and a hundred-fold to several thousand-fold, one man being able to accomplish as much as a small army in all previous ages." "That is to say," said the teacher, "it would seem that while the needs of the human race had not increased, its power to supply those needs had been indefinitely multiplied. This prodigious increase in the potency of labor was a clear net economic gain for the world, such as the previous history of the race furnished nothing comparable to. It was as if God had given to man his power of attorney in full, to command all the forces of the universe to serve him. Now, Harold, suppose you had merely been told as much as you have told us concerning the hundredfold multiplication of the wealth-producing power of the race which took place at this period, and were left, without further information, to infer for yourself how great a change for the better in the condition of mankind would naturally follow, what would it seem reasonable to suppose?"