An excerpt from the PREFACE: This Handbook of Mathematics is designed to contain, in compact form, accurate statements of those facts and formulas of pure mathematics which are most likely to be useful to the worker in applied mathematics. It is t intended to take the place of the larger compendiums of pure mathematics on the one hand, or of the technical handbooks of engineering on the other hand; but in its own field it is thought to be more comprehensive - than any other similar work in English. Many topics of an elementary character are presented in a form which permits of immediate utilization even by readers who have had previous acquaintance with the subject; for example, the practical use of logarithms and logarithmic cross-section paper, and the elementary parts of the modern method of mography (alignment charts), can be learned from this book without the necessity of consulting separate treatises. Other sections of the book to which special attention may be called are the chapter on the algebra of complex (or imaginary) quantities, the treatment of the catenary (with special tables), and the brief resume of the theory of vector analysis. The mathematical tables (including several which are t ordinarily found) are carried to four significant figures throughout, and pains have been spared to make them as nearly self-explanatory as possible, even to the reader who makes only occasional use of such tables. For the Tables of Weights and Measures, which add greatly to its usefulness, the book is indebted to Mr. Louis A. Fischer of the U. S. Bureau of Standards.