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ONE:In view of these propositions, I need hardly say to what object machine improvements should be directed, nor which of the considerations named are most affected by a combination of machine functions; the fact is, that if estimates could be prepared, showing the actual effect of machine combinations, it would astonish [70] those who have not investigated the matter, and in many cases show a loss of the whole cost of such machines each year. The effect of combination machines is, however, by no means uniform; the remarks made apply to standard machines employed in the regular work of an engineering or other establishment. In exceptional cases it may be expedient to use combined machines. In the tool-room of machine-shops, for instance, where one man can usually perform the main part of the work, and where there is but little space for machines, the conditions are especially favourable to combination machines, such as may be used in milling, turning, drilling, and so on; but wherever there is a necessity or an opportunity to carry on two or more of these operations at the same time, the cost of separate machines is but a small consideration when compared with the saving of labour that may be effected by independent tools to perform each operation. The tendency of manufacturing processes of every kind, at this time, is to a division of labour, and to a separation of each operation into as many branches as possible, so that study spent in "segregating" instead of "aggregating" machine functions is most likely to produce profitable results.The keynote of the whole poem is struck in its opening lines. When Venus is addressed as Nature��s sole guide and ruler, this, from the poet��s own point of view, is not true of Nature as a whole, but it is eminently true of life, whether we identify Venus with the passion through which living things are continually regenerated, or with the pleasure which is their perpetual motive and their only good. And it is equally appropriate, equally characteristic of a consummate artist, that the interest of the work should culminate in a description of107 this same passion, no longer as the source of life, but as its last outcome and full flower, yet also, when pushed to excess, the illusion by which it is most utterly disappointed and undone; and that the whole should conclude with a description of death, not as exemplified in any individual tragedy, but in such havoc as was wrought by the famous plague at Athens on man and beast alike. Again, it is by the orderly sequence of vital phenomena that Lucretius proves his first great principle, the everlasting duration and changelessness of matter. If something can come out of nothing, he asks us, why is the production of all living things attached to certain conditions of place and season and parentage, according to their several kinds? Or if a decrease in the total sum of existence be possible, whence comes the inexhaustible supply of materials needed for the continual regeneration, growth, and nourishment of animal life? It is because our senses cannot detect the particles of matter by whose withdrawal visible objects gradually waste away that the existence of extremely minute atoms is assumed; and, so far, there is also a reference to inorganic bodies; but the porosity of matter is proved by the interstitial absorption of food and the searching penetration of cold; while the necessity of a vacuum is established by the ability of fish to move through the opposing stream. The generic differences supposed to exist among the atoms are inferred from the distinctions separating not only one animal species from another, but each individual from all others of the same species. The deflection of the atoms from the line of perpendicular descent is established by the existence of human free-will. So also, the analysis which distinguishes three determinate elements in the composition of the soul finds its justification in the diverse characters of animals��the fierceness of the lion, the placidity of the ox, and the timorousness of the deer��qualities arising from the preponderance of a fiery, an a?rial, and a windy ingredient in the animating principle of each respectively. Finally, by another organic108 illustration, the atoms in general are spoken of as semina rerum��seeds of things.

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