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TWO:Founding and casting relate to forming parts of machinery by pouring melted metal into moulds, the force of gravity alone being sufficient to press or shape it into even complicated forms. As a process for shaping such metal as is not injured by the high degree of heat required in melting, moulding is the cheapest and most expeditious of all means, even for forms of regular outline, while the importance of moulding in producing irregular forms is such that without this process the whole system of machine construction would have to be changed. Founding operations are divided into two classes, known technically as green sand moulding, and loam or dry sand moulding; the first, when patterns or duplicates are used to form the moulds, and the second, when the moulds are built by hand without the aid of complete patterns. Founding involves a knowledge of mixing and melting metals such as are used in machine construction, the preparing and setting of cores for the internal displacement of the metal, cooling and shrinking strains, chills, and many other things that are more or less special, and can only be learned and understood from actual observation and practice.

TWO:It would appear that even in the Pythagorean school there had been a reaction against a doctrine which its founder had been the first to popularise in Hellas. The Pythagoreans had always attributed great importance to the conceptions of harmony and numerical proportion; and they soon came to think of the soul as a ratio which the different elements of the animal body bore to one another; or as a musical concord resulting from the joint action of its various members, which might be compared to the strings of a lute. But