This text is offered to teachers of elementary physics with the hope that it will not only prove to be teachable in method, but also that it may possess that "human touch" which will make it interesting to read as well as profitable to study.<br><br>The chief characteristics of the book are:<br><br>(a) Content: The essentials of elementary physics.<br><br>(b) Language: Simple in style and accurate in statement.<br><br>(c) Illustrations: Of the five hundred and fifty illustrations used more than three hundred are line engravings, especially prepared to serve as part of the regular recitation work.<br><br>(d) Exercise: The exercises and problems are simple in content and are placed in the text in immediate connection with the topics which they were written to explain.<br><br>(e) Supplement: Herein is placed a large amount of supplementary material, as for example: (a) Presentation of topics of special interest to certain localities and individual students, (b) discussion of modern theories, such as the electron theory of matter, (c) biographical sketches, (d) tables of physical constants, (e) supplementary problems. This supplementary material is classified and placed in order, where it may be made use of as occasion and opportunity demand. The authors desire to thank their colleagues, of the University of Michigan, Dr. Karl E. Guthe, Dean of the Graduate Department, Prof. N. H. Williams, and Mr. L. D. Rich, for a careful and critical reading of the manuscript.