TWO:At the same time Lucretius is resolved that no false analogy shall obscure the distinction between life and the conditions of life. It is for attempting, as he supposes, to efface this distinction that he so sharply criticises the earlier Greek thinkers. He scoffs at Heracleitus for imagining that all forms of existence can be deduced from the single element of fire. The idea of evolution and transformation seems, under some of its aspects, utterly alien to our poet. His intimacy with the world of living forms had accustomed him to view Nature as a vast assemblage of fixed types which might be broken up and reconstructed, but which by no possibility could pass into one another. Yet this rigid retention of characteristic differences in form permits a certain play and variety of movement, an individual spontaneity for which no law can be prescribed. The foedera Naturai, as Prof. Sellar aptly observes, are opposed to the foedera fati.206 And109 this is just what might be expected from a philosophy based on the contemplation of life. For, while there is no capriciousness at all about the structure of animals, there is apparently a great deal of capriciousness about their actions. On the other hand, the Stoics, who derived their physics in great part from Heracleitus, came nearer than Lucretius to the standpoint of modern science. With them, as with the most advanced thinkers now, it is the foedera Naturaithe uniformities of co-existencewhich are liable to exception and modification, while the foedera fatithe laws of causationare necessary and absolute.
THREE:This was the creed professed by the great scientific school of antiquity, and this was its way of protesting against the contempt of physics which prevailed among the Stoics!Judged upon theoretical grounds, and leaving out the mechanical conditions of operation, it would at once be conceded that a proper plan would be to move the lightest body; that is, if the tools and their attachments were heavier than the material to be acted upon, then the material should be moved for the cutting action, and vice versa. But in practice there are other conditions to be considered more important than a question of the relative weight of reciprocating parts; and it must be remembered that in solving any problem pertaining to machine action, the conditions of operation are to be considered first and have precedence over problems of strain, arrangement, or even the general principles of construction; that is, the conditions of operating must form a base from which proportions, arrangements, and so on, must be deduced. A standard planing machine, such as is employed for most kinds of work, is arranged with a running platen or carriage upon which the material is fastened and traversed beneath the cutting tools. [130] The uniformity of arrangement and design in machines of this kind in all countries wherever they are made, must lead to the conclusion that there are substantial reasons for employing running platens instead of giving a cutting movement to the tools.
THREE:The time in which the contraction takes place is as the temperature of the bath and the cross section of the piece; in other words the heat passes off gradually from the surface to the centre.It began to dawn upon Ren that the speaker was right. But he had another weapon still up his sleeves. His vengeance was not boiling within him as it had been, the red light no longer danced before his eyes.
THREE:
