
TWO:Two passages in Aristotles writings have been supposed to give evidence of his admiration for Alexander. One is the description of the magnanimous man in the Ethics. The other is a reference in the Politics to an ideal hero, whose virtue raises him so high above the common run of mortals that their duty is to obey him as if he were a god. But the magnanimous man embodies a grave and stately type of character quite unlike the chivalrous, impulsive theatrical nature of Alexander,177 while probably not unfrequent among real Hellenes; and the god-like statesman of the Politics is spoken of rather as an unattainable ideal than as a contemporary fact. On the whole, then, we must conclude that the intercourse between these two extraordinary spirits has left no distinct trace on the actions of the one or on the thoughts of the other.5. Every part laid down has something to govern it that may be termed a "base"some condition of function or position which, if understood, will suggest size, shape, and relation to other parts. By searching after a base for each and every part and detail, the draughtsman proceeds upon a regular system, continually maintaining a test of what is done. Every wheel, shaft, screw or piece of framing should be made with a clear view of the functions it has to fill, and there are, as before said, always reasons why such parts should be of a certain size, have such a speed of movement, or a certain amount of bearing surface, and so on. These reasons or conditions may be classed as expedient, important, or essential, and must be estimated accordingly. As claimed at the beginning, the designs of machines can only in a limited degree be determined by mathematical data. Leaving out all considerations of machine operation with which books have scarcely attempted to deal, we have only to refer to the element of strains to verify the general truth of the proposition.