WORKS OF WILLIAM KENT PUBLISHED BY JOHN WILEY & SONS. The Mechanical Engineers' Pocket-Book. A Reference Book of Rules, Tables, Data, and Formulæ, for the Use of Engineers, Mechanics, and Students. xxxii+1100 pages, 16mo, morocco, $5.00. Steam-Boiler Economy. A Treatise on the Theory and Practice of Fuel Economy in the Operation of Steam-Boilers. xiv +458 pages, 136 figures, 8vo, cloth, $4.00. THE MECHANICAL ENGINEER'S POCKET-BOOK. A REFERENCE-BOOK OF RULES, TABLES, DATA, ENGINEERS, MECHANICS, AND STUDENTS. BY WILLIAM KENT, A.M., M.E., Dean and Professor of Mechanical Engineering in the L. C. Smith Member Amer. Soc'y Mechl. Engrs. and Amer. Inst. Mining Engrs. SEVENTH EDITION, REVISED AND ENLARGED FIFTEENTH THOUSAND. TOTAL ISSUE FIFTY THOUSAND. NEW YORK: JOHN WILEY & SONS. 0621 COPYRIGHT, 1895, 1902, BY WILLIAM KENT. PRESS OF BROOKLYN, N. Y. Jan 24, 1941 PREFACE. MORE than twenty years ago the author began to follow the advice given by Nystrom: "Every engineeer should make his own pocket-book, as he proceeds in study and practice, to suit his particular business." The manuscript pocket-book thus begun, however, soon gave place to more modern means for disposing of the accumulation of engineering facts and figures, viz., the index rerum, the scrapbook, the collection of indexed envelopes, portfolios and boxes, the card catalogue, etc. Four years ago, at the request of the publishers, the labor was begun of selecting from this accumulated mass such matter as pertained to mechanical engineering, and of condensing, digesting, and arranging it in form for publication. In addition to this, a careful examination was made of the transactions of engi neering societies, and of the most important recent works on mechanical engineering, in order to fill gaps that might be left in the original collection, and insure that no important facts had been overlooked. Some ideas have been kept in mind during the preparation of the Pocket-book that will, it is believed, cause it to differ from other works of its class. In the first place it was considered that the field of mechanical engineering was so great, and the literature of the subject so vast, that as little space as possible should be given to subjects which especially belong to civil engineering. While the mechanical engineer must continually deal with problems which belong properly to civil engineering, this latter branch is so well covered by Trautwine's "Civil Engineer's Pocketbook" that any attempt to treat it exhaustively would not only fill no "long-felt want," but would occupy space which should be given to mechanical engineering. "" an au Another idea prominently kept in view by the author has been that he would not assume the position of thority" in giving rules and formulæ for designing, but only that of compiler, giving not only the name of the originator of the rule, where it was known, but also the volume and page from which it was taken, so that its iii derivation may be traced when desired. When different formulæ for the same problem have been found they have been given in contrast, and in many cases examples have been calculated by each to show the difference between them. In some cases these differences are quite remarkable, as will be seen under Safety-valves and Crank-pins. Occasionally the study of these differences has led to the author's devising a new formula, in which case the deriva tion of the formula is given. Much attention has been paid to the abstracting of data of experiments from recent periodical literature, and numerous references to other data are given. In this respect the present work will be found to differ from other Pocketbooks. The author desires to express his obligation to the many persons who have assisted him in the preparation of the work, to manufacturers who have furnished their catalogues and given permission for the use of their tables, and to many engineers who have contributed original data and tables. The names of these persons are mentioned in their proper places in the text, and in all cases it has been endeavored to give credit to whom credit is due. The thanks of the author are also due to the following gentlemen who have given assistance in revising manuscript or proofs of the sections named: Prof. De Volson Wood, mechanics and turbines; Mr. Frank Richards, compressed air; Mr. Alfred R. Wolff, windmills; Mr. Alex. Humphreys, illuminating gas; Mr. Albert E. Mitchell, locomotives; Prof. James E. Denton, refrigerating-ma chinery; Messrs. Joseph Wetzler and Thomas W. Varley, electrical engineering; and Mr. Walter S. Dix, for valuable contributions on several subjects, and suggestions as to their WILLIAM KENT. treatment. PASSAIC, N. J., April, 1895. FIFTH EDITION, MARCH, 1900. C. Some typographical and other errors discovered in the fourth edition have been corrected. New tables and some additions have been made under the head of Compressed Air. The new (1899) code of the Boiler Test Committee of the American Society of Mechanical Engineers has been substituted for the old (1885) code. W. K. |