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THREE:In no other branch of machinery has so much research and experiment been made during eighty years past as in steam machinery, and, strange to say, the greater part of this research has been directed to the details of engines; yet there has been no improvement made during the time which has effected any considerable saving of heat or expense. The steam-engines of fifty years ago, considered as steam-using machines, utilised nearly the same proportion of the energy or power developed by the boiler as the most improved engines of modern construction��a fact that in itself indicates that an engine is not the vital part of steam machinery. There is not the least doubt that if the efforts to improve steam-engines had been mainly directed to economising heat and increasing the evaporative power of boilers, much more would have been accomplished with the same amount of research. This remark, however, does not apply to the present day, when the principles of steam-power are so well understood, and when heat is recognised as the proper element to deal with in attempts to diminish the expense of power. There is, of course, various degrees of economy in steam-using as well as in steam-generating machinery; but so long as the best steam machinery does not utilise but one-tenth or one-fifteenth part of the heat represented in the fuel burned, there need be no question as to the point where improvements in such machinery should be mainly directed.

THREE:Formerly an apprentice entered a shop to learn hand skill, and to acquaint himself with a number of mysterious processes; to learn a series of arbitrary rules which might serve to place him at a disadvantage even with those whose capacity was inferior and who had less education; but now the whole is changed. An engineer apprentice enters the shop with a confidence that he may learn whatever the facilities afford if he will put forth the required efforts; there are no mysteries to be solved; nearly all problems are reached and explained by science, leaving a greater share of the shop-time of a learner to be devoted to studying what is special.How many soldiers had fallen in consequence of this attack by francs-tireurs he knew not; which troops had witnessed the occurrence he could not say. All he did know was that these troops had left in the morning, leaving a small force behind to impose the punishment.

THREE:"Now what does it mean?" he asked himself. "What game were they playing?"