Читать книгу The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking - Paul N. Hasluck - Страница 81

THE saw cannot be classified with any other tool. The hammer is a tool for consolidating material; the splitting axe, although usually regarded as an edge tool, is generally a hammer with a wedge pane, and is used for dividing material in the line of the fibres. The true edge tool in its most elementary form is the chisel, and by various added contrivances the chisel becomes the shears and the plane; but saws, which are to be discussed in this chapter, differ from all these. They can scarcely be called derivatives from these, unless the knife be regarded as the connecting link; for sometimes it is used as a chisel and at other times as a saw. All these tools, including the knife, cut or work in the direction of the grain or fibre, but the saw is essentially a tool for use across or at right angles to this fibre, although custom and convenience have arranged the saw for use with the fibre. Even then it is only because the fibres are not straight and parallel. When they are so, as in lath wood, then the saw is not employed. It is true that in such work as the felling of timber the axe is used across the grain, and therefore at right angles to the length of the fibre; yet if the action of the forester be observed, it will be seen that the direction of his blow is not that of the line of separation. He goes at his work indirectly when using the axe, directly when using the saw. These and the following remarks on the theory of the saw’s action and application are taken from Rigg’ Cantor Lectures, to which reference has been made already.