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THREE:In adding another to the large number of books which treat upon Mechanics, and especially of that class devoted to what is called Mechanical Engineering, it will be proper to explain some of the reasons for preparing the present work; and as these explanations will constitute a part of the work itself, and be directed to a subject of some interest to a learner, they are included in the Introduction.IX.

THREE:The old age of Plato seems to have been marked by restless activity in more directions than one. He began various works which were never finished, and projected others which were never begun. He became possessed by a devouring zeal for social reform. It seemed to him that nothing was wanting but an enlightened despot to make his ideal State a reality. According to one story, he fancied that such an instrument might be found in the younger Dionysius. If so, his expectations were speedily disappointed. As Hegel acutely observes, only a man of half measures will allow himself to be guided by another; and such a man would lack the energy needed to carry out Plato’s scheme.158 However this may be, the philosopher does not seem to have given up his idea that absolute monarchy was, after all, the government from which most good might be expected. A process of substitution which runs through his whole intellectual evolution was here exemplified for the last time. Just as in his ethical system knowledge, after having been regarded solely as the means for procuring an ulterior end, pleasure, subsequently became an end in itself; just as the interest in knowledge was superseded by a more absorbing interest in the dialectical machinery which was to facilitate its acquisition, and this again by the social re-organisation which was to make education a department of the State; so also the beneficent despotism originally invoked for the purpose of establishing an aristocracy on the new model, came at last to be regarded by Plato as itself the best form of government. Such, at least, seems to be the drift of a remarkable Dialogue called the Statesman, which we agree with Prof. Jowett in placing immediately before the Laws. Some have denied its authenticity, and others have placed it very early in the entire series of Platonic compositions. But it contains passages of269 such blended wit and eloquence that no other man could have written them; and passages so destitute of life that they could only have been written when his system had stiffened into mathematical pedantry and scholastic routine. Moreover, it seems distinctly to anticipate the scheme of detailed legislation which Plato spent his last years in elaborating. After covering with ridicule the notion that a truly competent ruler should ever be hampered by written enactments, the principal spokesman acknowledges that, in the absence of such a ruler, a definite and unalterable code offers the best guarantees for political stability.

THREE:“I’ll have you calling me ‘Successful Sandy’ before I’m through.”

THREE:Et merito: nam si certain finem esse viderentAs to the manner of cutting out or planing up the lumber for patterns, and the manner of framing them together, it is useless to devote space to the subject here; one hour's practical observation in a pattern-shop, and another hour spent in examining different kinds of patterns, is worth more to the apprentice than a whole volume written to explain how these last-named operations are performed. A pattern, unless finished with paint or opaque varnish, will show the manner in which the wood is disposed in framing the parts together.

THREE:Let the reader compare a hammer with a wheel and axle, inclined plane, screw, or lever, as an agent for concentrating and applying power, noting the principles of its action first, and then considering its universal use, and he will conclude that, if there is a mechanical device that comprehends distinct principles, that device is the common hammer. It seems, indeed, to be one of those provisions to meet a human necessity, and without which mechanical industry could not be carried on. In the manipulation of nearly every kind of material, the hammer is continually necessary in order to exert a force beyond what the hands may do, unaided by mechanism to multiply their force. A carpenter in driving a spike requires a force of from one to two tons; a blacksmith requires a force of from five pounds to five tons to meet the requirements of his work; a stonemason applies a force of from one hundred to one thousand pounds in driving the edge of his tools; chipping, calking, in fact nearly all mechanical operations, consist more or less in blows, such blows being the application of accumulated force expended throughout a limited distance.