course usually prescribed in Mercantile and Commercial Colleges, yet those subjects requisite to make good accountants, and which have been taught orally in that class of institutions from want of a suitable text-book, are fully discussed and practically applied in this work; and it is therefore believed to be better adapted to the wants of Mercantile Colleges than any similar work yet published. And while it is due, it is also proper here to state that J. C. Porter, A. M., an experienced and successful teacher of Mathematics in this State, and formerly professor of Commercial Arithmetic, in Iron City Commercial College, Pittsburgh, Penn., has rendered valuable aid in the preparation of the above-named subjects, and of other portions of the work. He is likewise the author of the Factor Table on pages 72 and 73, and of the new and valuable improvement in the method of Cube Root. Teachers entertain various views relative to having the answers to problems and examples inserted in a text-book. Some desire the answers placed immediately after the examples; others wish them placed together in the back part of the book; and still others desire them omitted altogether. All these methods have their advantages and their disadvantages. If all the answers are given, there is danger that the pupil will become careless, and not depend enough upon the accuracy of his own computations. Hence he is liable to neglect the cultivation of those habits of patient investigation and self-reliance which would result from his being obliged to test the truth and accuracy of his own processes by proof,—the only test he will have to depend upon in all the computations in real business transactions in after life. Besides, the work of proving the correctness of a result is often of quite as much value to the pupil as the work of performing the operation; as the proof may render simple and clear some part or the whole of an operation that was before complicated and obscure. The improvements in Percentage made necessary by the financial changes of the last few years are especially noticeable. The different kinds of United States' Securities, Bonds, and Treasury Notes are described, and their com parative value in commercial transactions illustrated by practical examples. The difference between Gold and Currency, and the corresponding difference in prices, exhibited in trade, are taught and illustrated, and many other things that every commercial student and business man ought to know and understand. AUGUST, 1860. IMPROVED EDITION. Such changes only have been made in the present edition as were necessary to conform to law and usage, and to meet a demand from many of the best teachers of the country for a full and practical treatise on Mensuration. Hence Foreign Exchange has been so modified in the Tables and Examples as to conform to the Act of March 3, 1873, and to present usage. Thirty-six pages of useful and practical matter on Mensuration and Measurements, have been carefully prepared and substituted at the end of the book for the lengthy treatise of the Metric System heretofore presented, and which is scarcely ever used in this country. To avoid repetition, as well as to put in a more condensed form, the Principles and Applications of the Square and Cube roots that intervened between "Evolution" and "Series" in former editions, have been embodied in these thirty-six pages, and also so much of the Metric System as is of any practical value. It is hoped that these improvements will give new life to a book that has already proved its merits by the large and increasing circulation it has obtained. JULY, 1875. |