The great object of the geologist is, by studying the geological formations in regular order, from the oldest up to the newest, to work out, in their proper sequence, the events which constitute the earth’s history; and dynamical and structural geology are merely introductory chapters, the alphabet, as it were, which must be learned before we are prepared to read understandingly the grand story of the geological record. Our work in this short course will be limited to the first two divisions,—_i.e._, to dynamical and structural geology. We will attempt, first, a general sketch of the forces now concerned in the formation of rocks and rock-structures; and after that we will study the composition and other characteristics of the common minerals and rocks. The scope of this work, and its relations to the whole field of geology, are more clearly indicated by the following classification of the geological sciences:— {DYNAMICAL GEOLOGY {_Physical Geology._ {_Chemical Geology._ GEOLOGY {STRUCTURAL GEOLOGY {_Mineralogy._ {_Petrography_ {Lithology. {Petrology. {HISTORICAL GEOLOGY. Many teachers will desire to fill in some of the details of the outline sketch presented in this Guide, and for this purpose the following works are especially recommended:— ELEMENTS OF GEOLOGY. By Prof. Joseph Le Conte. 1882. D. Appleton & Co., New York. Nearly 600 pages. MANUAL OF GEOLOGY. By Prof. J. D. Dana. Third edition. 1880. 800 pages. TEXT-BOOK OF GEOLOGY. By Prof. A. Geikie. 1882. Macmillan & Co., London. Nearly 1000 pages. As a reference-book for mineralogy, the following treatise is unsurpassed:— TEXT-BOOK OF MINERALOGY. By Edward S. Dana. 1883. John Wiley & Sons, New York. And, as an introduction to the study of minerals, and, through these, to the study of rocks,— FIRST LESSONS IN MINERALS. Science Guide No. XIII. By Mrs. E. H. Richards. cannot be too highly recommended. Teachers will find this little primer of 46 pages invaluable with young children, and with all who have had no previous training in chemistry. As an admirable continuation of the work begun in these pages, teachers are referred to Professor Shaler’s “First Book in Geology.” In this our brief sketch of the geological agencies is amplified and beautifully illustrated; and rarely have the wonderful stories of the river, ocean-beach, glacier, and volcano been told so effectively. In the chapter on the history of life on the globe the main outlines of historical geology are skillfully brought within the comprehension of beginners. The directions to teachers are fully in accord with the modern methods and ideas, and are a very valuable feature of the book. ------------------------------------------------------------------------