STANDARD PRACTICAL PLUMBING: AN EXHAUSTIVE TREATISE ON ALL BRANCHES OF PLUMBING CONSTRUCTION INCLUDING DRAINAGE AND VENTING, VENTILATION, HOT AND THE WORK SHOWS THE LATEST AND BEST PLUMBING A SPECIAL FEATURE: 347 ORIGINAL ILLUSTRATIONS, EACH NEW YORK The Norman W. Henley Publishing Company 2 WEST 45th STREET MARVARD UNIVERSITY DIVISION OF EDUCATION BURZAU OF VOCATIONAL CUIDANCE HARVARD COLLESE LIBRANY TRANSFERRED FROM THE LIBRARY OF THE BRADUATE SCHOOL OF EDUCATION 1941 COPYRIGHTED, 1910, BY THE NORMAN W. HENLEY PUBLISHING COMPANY PREFACE In general, the writing of works such as that which the author herewith presents, is accompanied by several features the effect of which is to materially lessen the excellent results which such a work should produce. One of the errors to which we allude, is the tendency of the author on trade subjects to write in too technical a manner, that is, to handle his subject in such a manner that none but the most educated of his readers are able to thoroughly grasp the principles - presented. For instance, since the plumber is seldom to be found who can handle an algebraic equation, it would certainly seem far better to present a necessary principle by means of arithmetic rather than by means of algebra, and if there is no other way than by means of algebra the author should see to it that he fully explains the entire operation at length, in such a manner that the reader who has not had the advantage of instruction in such branches may be able to grasp the subject. In other words, the author should stand in the same position to his readers that the teacher does to his pupils. It is his duty to honestly instruct, and not merely to fill his pages with facts which, though valuable, are presented in such a manner as not to be easily understood by the average reader. A second serious though unintentional error on the part of many authors is the omission of minor details. While to the author, who is naturally a man of experience and education in his special line of work, the statement of simple, and to him obvious, facts seems a matter of foolishness, ofttimes, to many of his younger and more inexperienced readers, the statement of these simple things is a matter of utmost importance, and a means of establishing the main principle more strongly in their minds. The author of this work frankly confesses to surprise at the absence of knowledge of rudiments which he knows from long |