The title of the present volume appears to be sufficiently descriptive without additional explanation, consequently the author will alone offer a few words on the notions which led to the division of the volume into the eight chapters enumerated in the table of contents, and on their particular arrangement.

The chisel was selected as the subject of the first chapter, as from the simplicity of its form and action, it may be viewed as a keen wedge, sometimes employed with quiet pressure, at other times used with percussion, as in tools of the character of axes and adzes; and the straight chisel mounted in a stock for its guidance becomes the plane. Further, the carpenter's chisel may be used as a turning tool, and many tools of this kind, the second in the classification, follow the condition of chisels and planes, if we imagine the tool to be held at rest, and the work to revolve against it, on a fixed axis. The practice of turning is naturally associated with that of boring holes, although in most cases, the boring tool revolves whilst the work remains at rest. Turning and boring, each circulatory processes, led to the selection of the screw as the subject of the next chapter, for revolution combined with rectilinear advance, are exhibited in all the numerous modes of producing screws.

Saws were ideally compared with some of the scraping chisels, but with a multiplication of points, and these sometimes arranged in continuous order as in the circular saw. The file from its vast assemblage of scraping teeth, was likened to a multiplication of the saw; but unfortunately the file has not been engrafted upon any machine, embodying the manipulation of the unassisted instrument. Shears and punches are next considered in great measure as parallel subjects, and the rectilinear edges of shears although mostly duplicated, nevertheless bear some resemblance to simple chisels, although from their duplication they act on both sides of the material; and lastly the ordinary punch is comparable with the rectilinear edges of the shears and chisels, if we do but conceive these to be bent into the circular form.

Should these grounds for the arrangement adopted be deemed fanciful or visionary, it may be added that some order or selection was imperative, and it is hoped the present will serve as efficiently as any other that could be selected.