Tool, a general term denoting any small implement, which is used both for manufacturing other complex instruments or machines, and also those employed in the mechanical arts.

Tools are divided into edged-tools, spring-tools, pointed-toolst etc. But, consistently with the advanced state of the present work, we shall only give an account of a patent, granted in January 1795t to Mr. Arnold Wilde, for making plane-irons, sickles, scythes, drawing-knives, and all other kinds of edged-tools, from a preparation of cast-steel and iron, incorporated by means of fire. - He directs a piece of wrought-iron to be previously heated in the fire, and hammered ; after which it should be formed of the requisite size : it is then to be fixed in a mould of proper dimensions, and in such a direction that, when the cast-steel is poured into the latter, the iron may settle in the middle, or on either side. Next, the steel must be melted in a crucible exposed to a strong fire; and, when it is nearly in a fluid state, the iron should be prepared in a welding heat. After clearing it from scales, or other extraneous matters, the iron is again to be fixed in the mould, and the fluid steel poured into the vacancy left for that purpose; when the whole will be united into one solid mass. - The various tools, above-mentioned, may then be made of such compound metal in the usual manner; or by any method that should be deemed most; convenient to the workman, or, manufacturer.