Now, the reader need not be here told that the plan of an Annual Register of Inventions and Improvements originated in _The Mirror_ about four years since. Our intention there was to quote an occasional page or two of novelties of popular interest in science and art, and leave more abstruse matters to the journals in which they originally appeared. This plan led us through most of the scientific records of the year, in which we began to perceive that the reduction of all subjects of importance was not compatible within a few pages, and sooner than allow many papers of value to every member of society to be locked under the uninviting denomination of _philosophy_, we undertook the abridgement and arrangement of such papers, upon the plan of an "Annual Register," intending our volume specially to represent the progress of discovery just as the general "Register" is a contribution to history. The cost of the journals for this purpose proved to be upwards of Twelve Guineas, but this outlay only made us more pleased with the design. A single instance will suffice. The _Philosophical Magazine_, a work of high character, numbers among its purchasers but few general readers: it contains many mathematical, theoretical, and controversial papers, all of which may advance their object, but are not in a form sufficiently tangible for any but the scientific inquirer. Still, in the same Magazine, there may be papers of practical and directly useful character, and of ready application to the arts and interests of life and society. A person wishing to possess these popular papers must therefore purchase with them a quantity of matter which to him would be unintelligible, and the value of which could only be appreciated by direct study, a task of no small import in these days of cheap literature. That the plan has succeeded, and that its intention has been fully recognised, is borne out by the testimony of a score of our contemporaries. Of their praise we have no disposition to make an idle boast; and our only object in the present notice is to do for ourselves what we could not perhaps expect a weekly or monthly critic to do for us, viz. to quote the subjects of a few of the valuable papers in the present volume, and then leave the reader to form his own conclusions of its intrinsic value. In _Mechanical Science_ there are 100 closely-printed pages, or 90 articles. Among these are papers on novel applications of the gigantic power of _Steam_ in Navigation and Agriculture, and especially in Railway Carriages; the grand invention of the Air Engine; improvements in Printing; machinery in manufactures; and contributions to experimental as well as practical mechanics.