FOR MARINE ENGINEERS AND STUDENTS WITH Aids for Applicants for Marine Engineers' Licenses Fourth Edition Revised and Enlarged By CAPTAIN C. W. DYSON, U. S. N. BUREAU OF STEAM ENGINEERing, United STATES NAVY. Author of "Screw Propellers and Estimation of Power for Propulsion of Ships" New York Preface to First T HE purpose of the author in the preparation of this work has been to provide help for the operative or practical marine engineer, either for the man who has already entered the profession, but who may wish to perfect himself more fully in many branches of the subject, or for the applicant for the lowest round of the ladder, or for the young man whose attention is first turning to this field, and who may wish some simple and fairly complete presentation of the subject from the practical standpoint. The treatment of the subject throughout has thus been with a view to simplicity, but without undue sacrifice of generality or exactness of statement. It has been the desire of the author to bring the subject, so far as treated in the present work, within the grasp of those who have not had the advantages of higher mathematical and engineering education, but who may wish, nevertheless, to fit themselves for positions of honor and responsibility in the field of operative marine engineering. With this end in view only such parts of the general field of engineering have been included as are of special interest to the practical marine engineer. On these topics, however, the attempt has been made to give the largest amount of useful information in the simplest and most compact form. In the marine field itself, likewise, selection has been necessary, and many interesting parts of the subject have been omitted or briefly referred to in order to give more room for the practical side of the subject. Thus the book does not treat of the designing of marine machinery except in an incidental way. For the operative engineer the topics of greater importance are construction, operation, management and care. The simpler parts of the subject of design are, however, represented by the U. S. rules regarding the design and con 111 365553 เ struction of marine boilers, and by many hints regarding proportions and relations scattered throughout the work. In the chapters dealing descriptively with engines, boilers and auxiliaries, it has been impossible, of course, to describe exhaustively every form of design or appliance to be met with in marine practice. The purpose has been rather to describe typical or standard forms and to give the general conditions which the various parts must fulfill. The illustrations have been specially chosen with a view to supplement the text in these various particulars, and it is hoped that they will form not the least instructive and acceptable feature of the work. The subject of operation, management and repair has been given special attention, and it is hoped that this part of the work will be of value, especially to the young engineer lacking in practical experience. In Chapter XIV is gathered a collection of miscellaneous problems and discussions, many of which, it is hoped, will be of value to the professional engineer in connection with the various questions likely to arise in his experience. The chapters on valve gears and on indicator cards, while necessarily brief, are intended to present the fundamental features of the subject in such manner as to aid the novice and instruct and stimulate the professional engineer to a better understanding of these important branches of the subject. The chapter on propulsion and powering is necessarily brief, but the fundamental principles are given, with a few simple rules and the discussion of most of the problems commonly arising in practical engineering work. The chapters on refrigeration and on electricity on shipboard. are added in order to give the marine engineer some notion of the funamental principles controlling the operation of refrigerating and electric machinery, these two important auxiliaries of modern marine engineering practice. They are of necessity quite incomplete, especially Chapter X, but it is hoped that nevertheless they may be of aid to the marine engineer in understanding the mode of operation of such machinery, and in giving to it the proper care. In Chapter XV is given an elementary discussion of computations for engineers, or rather of the mathematics upon which such computations depend. A general knowledge of the subject is presupposed, but the more essential features of the elementary iv |