TOOL (0. Eng. tdl, generally referred to a

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• ROOT (late O.E. rot, adopted from Scand., cf. Norw. and Swed. rot, Dan. rod; the true O.E. word was wyrt, plant, represented in Ger. Wurz or Wurzel; the ultimate root is the same in both words, and is seen in Lat. radix)
• ROOT, ELIHU (1845– )

root seen in the Goth. taujan, to make, or in the

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• ENGLISH

English word " taw," to

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• WORK

work or

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• DRESS (from the Fr. dresser, to set out, arrange, formed from Lat. directus, arranged, dirigere, to direct, arrange)

dress

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• LEATHER (a word which appears in all Teutonic languages; cf. Ger. Leder, Dutch leer or leder, Swed. leder, and in such Celtic forms as Welsh llader)
• LEATHER, ARTIFICIAL

leather)  , an implement or appliance used by a worker in the treatment of the substances used in his handicraft, whether in the preliminary operations of setting out and measuring the materials, in reducing his work to the required form by cutting or otherwise, in gauging it and testing its accuracy, or in duly securing it while thus being treated . For the tools of prehistoric man see such articles as ARCHAEOLOGY ; FLINT IMPLEMENTS; and EGYPT, § Art and Archaeology . In beginning a survey of tools it is necessary to draw the distinction between hand and machine tools . The former class includes any tool which is held and operated by the unaided hands, as a chisel, plane or saw . Attach one of these to some piece of operating mechanism, and it, with the environment of which it is the central essential object, becomes a machine tool . A very simple example is the common power-driven hack saw for metal, or the small high-speed drill, or the wood-boring auger held in a frame and turned by a winch handle and bevel-gears . The difference between these and a big frame-saw cutting down a dozen boards simultaneously, or the immense machine boring the cylinders of an ocean liner, or the great gun lathe, or the hydraulic press, is so vast that the relationship is hardly apparent . Often the tool itself is absolutely dwarfed by the machine, of which nevertheless it is the central object and around which the machine is designed and built . A milling machine weighing several tons will often be seen rotating a tool of but two or three dozen pounds' weight . Yet the machine is fitted with elaborate slides and self-acting movements, and provision for taking up wear,and is worth some hundreds of pounds sterling, while the tool may not be worth two pounds . Such apparent anomalies are in constant evidence . We propose, therefore, first to take a survey of the principles that underlie the forms of tools, and then pursue the subject of their embodiment in machine tools .