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FORE:To estimate how much is yet to be learned in mechanical engineering, we have only to apply the same test, and when we contrast the great variance between the designs of machines and the diversity of their operation, even when applied to similar purposes, their imperfection is at once apparent. It must, however, be considered that if the rules of construction were uniform, and the principles of machine operation as well understood as the strength and arrangement of material in permanent structures, still there would remain the difficulty of adaptation to new [15] processes, which are continually being developed.

FORE:The profit reaped by Aristotle from the connexion seems equally doubtful. Tradition tells us that enormous sums of money were spent in aid of his scientific researches, and a whole army of crown servants deputed to collect information287 bearing on his zoological studies. Modern explorations, however, have proved that the conquests of Alexander, at least, did not, as has been pretended, supply him with any new specimens; nor does the knowledge contained in his extant treatises exceed what could be obtained either by his own observations or by private enquiries. At the same time we may suppose that his services were handsomely rewarded, and that his official position at the Macedonian Court gave him numerous opportunities for conversing with the grooms, huntsmen, shepherds, fishermen, and others, from whom most of what he tells us about the habits of animals was learned. In connexion with the favour enjoyed by Aristotle, it must be mentioned as a fresh proof of his amiable character, that he obtained the restoration of Stageira, which had been ruthlessly destroyed by Philip, together with the other Greek cities of the Chalcidic peninsula.49