The practical engineer : a treatise on the subject of modeling, constructing and running steam engines. Containing, also, directions in regard to the various kinds of machinery connected with steam power ...

Front matter

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Preface To The First Edition

The author presents to the public this volume on ** Practical engineering,'' in the full confidence that such a work has long been desired, and js verj much needed bj the practical engineer, as well as those who have had little or no experience in this department of science, but whose business requires the aid of steam power. There have been many scientific works published upon the subject of steam, and various other matters connected therewith, altogether foreign from the object sought to be explained^ if they were, indeed, intended to assist and instruct the practical engineer. We venture the assertion that there are a hundred things, aye, a thousand, the knowl^edge of which would be beneficial to the practical engineer, which have not been alluded to nor mentioned in the books hitherto published on this important subject. The reason of this may be attributed to the fact that men of mere theory have undertaken to put forth books for the purpose of instructing practical men in matters which the authors have never learned, and about which they are totally ignorant. So far as the theory is correct, they are entitled to credit for its promulgation.

But abstract theory can never meet the wants of the practical engineer, and instruct and assist him in working steam engines. In other words, it is folly to assume that a theorist alone can be possessed of such a correct and practical knowledge of steam engines as will meet the hearty response and approbation of that class of persons for whose benefit this treatise is published. It will readily be conceded, then, that a work, in order to be useful, must issue from one who is acquainted not only with the theory but ^ii\i practical engineering ; and it must exhibit in every page evidence of the author's practical experience. When such is the case, practical nien will not only at once perceive the author's capability to explain ir

aud elucidate the different branches of the subject upon which h© writes, but will be much pleased and instructed by a perusal of the work. Such a book is now presented.

The author of this work has had experience in practical engineering, extending through many years, in various places, and with almost every description of engines. His sources of knowledge are therefore extensive, and the results of his information are given in the pages of this work in a plain, concise and practical style. He has been employed in constructing and working at engines of various kinds, in Pittsburgh, Wheeling, Cincinnati, Louisville, and New Albany, Ind.; and was for some length of time a practical engineer in running the Ohio and Tennessee rivers.

Bis knowledge of land and stationary engines is quite as extensive as that of most other persons, and he feels therefore confident of the utility of the present work to practical men.

The author has had in contemplation to publish a work of this character, for some eight or ten years, thinking that the public would be benefitted from its perusal ; but hoping to be anticipated by some one of merit and usefulness, the project was time after time abandoned. After having perused many works from which engineers (himself among them ) expected to derive benefit and information, and finding them wide off the point sought to be obtained, he was persuaded to enter on the task of compiling a book suited to the wants of the practical engineer.

This volume, therefore, has been written and compiled especially ^or the practical man ; but its pages will be found both interesting and instructive to engine builders. They w^ould do well to consult its pages previously to modeling machinery for steam engines. It is entitled -'The Practical Engineer,'^ and should be in the hands of every steamboat captain, as well as engineer. It will not only instruct him in many things of which he is ignorant respecting the machinery and workings of the engine, but will be of great use in enabling him to draw up an order for an engine, with so much clearness and accuracy as to enable ihe builders to perfectly understand what is required, and upon what terms it can be filled. This is an important consideration, and one which, unfortunately, captains have been heretofore too little acquainted with. It will also be found of interest and profit to the pilot to read this work, as it may lead him to the discovery of danger from the working of the engine, and excite bini to greater care in the discharge of his duty.

The secoud volume will be devoted to marine, factory, and other stationary engines.

In conclusion, I would say to the practical engineer, engine builder, captain and pilot of boats, make this book your study, so far as duty requires, and you will find that your time has not been lost; but, on the contrary, you will be possessed of such a general knowledge of steam er.gines, as you little thought of previous to its perusal ; and upon the strength of which you can each embark upon your respective duties with confidence, knowledge, and a certainty of greater success.

JOHN AVALLACE,

Pittsburgh, July I, 1853.

Preface To The Second Edition

In place of a second volume of the ** Practical Engineer," which the author in the above preface proposed to publish, he now presents to the public a second edition, improved and enlarged, of the work itself. The additional experience of eleven years in making all kinds of machinery connected with steam engines, enables him to add much to the utility of the book. The many testimonials that he has received of the benefit derived from perusing the "Practical Engineer," and the fact that the demand for it was urgent after the edition was exhausted, were both gratifying to him, and afforded a stimulus to exert himself to make the book still more worthy of public patronage.

In preparing this work the author has drawn chiefly on his own experience and observation. There are a few selections and tables from Brunton, Scribner, &c. ,* but in giving information on subjects so intimately connected with propertj^ and life as those which relate to steam machinery, he was not willing to put forward any thing the reality of which he had not tested.

JOHK WALLACE