In 1915, when the first edition of this text-book appeared, the author had had ten years’ experience in teaching Historical Geology in the Sheflield Scientific School of Yale University. Since then he has continued his interest in the subject, teaching it until 1920, and has made almost daily annotations in his table copy of the first edition concerning the newer facts as they appeared in publications. It soon became a perplexing problem to know what to eliminate so as to keep the book within bounds, as one intended for beginners in Geology rather than for matured geologists. A few teachers present Historical Geology in 15 hours, most of them take from 28 to 35 "hours, and now there is a strong tendency to extend the lectures and laboratory to 45 hours. Moreover, the fact that many American college students taking a year’s work in Geology have had no preparation in Zoology or Botany makes it necessary to include in the book some description, however brief, of the fundamental structures of living plants and animals. To cut the dilemma arising from such diverse needs on the part of the teachers, the author has concluded, after seeking advice from many who are presenting the subject in our colleges, to include in the book too much material rather than too little. Accordingly the new edition is larger by some 80 pages. For the 45-hour course the book is about the right length, and it is thought that the instructors of the shorter courses will know best what parts to eliminate.
Historical Geology is a most fascinating study, since it includes not only the physical history of the earth from the time of its solar origin, but as well the orderly appearance and evolution of all its life. It is therefore as much a biological science as it is a geological one, bringing together, into a connected whole, facts from sources as diverse as Structural and Stratigraphic Geology, Paleontology, Biology, Oceanography, and Astronomy. And perhaps more than any other branch of the geological sciences, Historical Geology leads into Philosophy, in the search for the meaning behind the story which it presents.
Because of its practical application to the weKare of man. Zoology has a tendency to push Historical Geology out of the present-day [ p. iv ]
curriculum. Geologists should not allow this to come about, since Historical Geology -proves man to be “the paragon of animals, the climax of evolution,” and all who drink deeply of this science will be compelled to work out their own philosophy of happiness. lif a full course in Historical Geology can not be given, it should at least have as much place in .the curriculum as can be kept for it.
The material upon which this book is based has naturally been drawn from so many sources and has become so integral a part of the writer’s fund of information that it is not easy to render complete acknowledgment. The well-known general treatises and works o’ Dana, Suess, LeConte, Chamberlin and Salisbury, Scott, Grabau Cleland, Coleman and Parks, Geikie, Kayser, Walther, Neumayr Credner, Jukes-Browne, Lapparent, and Haug are of course the main sources. Of great service have also been the more general works on paleontology of Zittel-Eastman, Osborn, Scott, and Williston; the zoologies of Thomson, Parker and Haswell, Lull, and Weysse; the wiorks on man by Sollas, Keith, Hxixley, and Osborn; the histories of Zittel, Geikie, and Merrill; the treatises on oceanography by Krümmel, Murray and Hjört, and Johnstone; astronomy as presented by Hale, Abbot, and Moulton; Clarke’s work on geochemistry; and, for stratigraphy, Willis’ great and comprehensive Index. Papers and books dealing with more special phases of the subject have been included in the list of “ Collateral Reading ” at the end of each chapter, which forms a new feature of this edition. Finally, the wealth of fact and illustration in the works of the United States Geological Survey, the Geological Survey of Canada, and the New York, Maryland, Illinois, Ohio, Indiana, Minnesota, and other state surveys has been drawn upon freely.
The writer is also much indebted to the United States Geological Survey and to Professor Bailey Willis for the great help given in the making of the geological map of North America which accompanies the book.
In the preparation of this edition, as of the former one, the author received much aid from the late Professors Louis V. Pirsson and Joseph Barrell, and from his colleagues. Professors Herbert E. Gregory and Richard S. Lull. Special thanks are due to his associate. Doctor Carl O. Dunbar, whose teaching of the subject has enabled him to offer constructive criticism on all parts of the book. Professor C. K. Leith of Wisconsin, Professor Adolph Knopf of Yale, Doctor Willet G. Miller of Toronto, and Director W. H. Collins of the Geological Survey of Canada have helped much to improve the chapters on the Archeozoic and Proterozoic. Thanks are also [ p. v ] due to his friends, Doctors T. W. Stanton and W. T. Lee, for special aid in the Mesozoic chapters, John M. Clarke for help in various places, and George Grant Mac.Curdy for criticism of the chapter oh man. Professor L. G. Westgate has made valuable suggestions in many places, and to Doctor A. K. Lobeck much is owed for the spirit of cooperation and the ability shown in depicting the physiography on six paleogeographic maps, another innovation in this edition.
Most of the pen drawings were made by Mr. William Baake, the remainder by Doctor Stanley C. Ball and Miss Lisbeth B. Krause. The author’s acknowledgments are also due to the publishing firms of Macmillan, Scribner’s, Ginn and Company, and Putnam, for the loan of illustrations.
To Miss Clara Mae LeVene the writer is especially grateful for her untiring helpfulness in both editions of this book, as well as in the second edition of Part I.
Finally, the author wishes to record his appreciation of the skill and patience shown by the Technical Composition Company in getting the book ready for the pressroom, and of the helpfulness and courtesy of Wiley and Sons during the preparation and publication of both editions.
CHARLES SCHUCHERT
Peabody Museum of Yale University, New Haven, Connecticut,
August, 1923