In preparing this work the author has endeavored to give to the Mechanic a volume that he can readily understand, though he may not have a full knowledge of the scientific terms commonly used in works of this kind. He has also aimed to give a full explanation of every subject treated of in as few words as possible. He had thought of adding an article on the proper speed of turning and planing metals; but as they vary so much in hardness, it is almost impossible to lay down any safe rule, and he has therefore concluded to omit it. He has also purposely omitted the subjects of Geometry and Machine Drawing, as they would have extended the volume beyond its proposed size; and, besides, there are already published many good treatises on these subjects. Asking, therefore, that due allowance may be made for all omissions and imperfections, he submits his little work to the hands of those for whom it is intended.