This text diffes in many respects from the conventional approach to geology, so it may be appropriate to indicate some of the objectives that led to its development. Most important and most difficult to realize was the ideal of a book embodying throughout the scientific method. It was felt that the material should alternate between an investigatory type, showing the use of the conclusions reached. Also, an ideal book should have organic inity; it should be developmental rather than topical. Chapter 2 should stem obviously from chapter 1, and use its materials and conclusions. In retrospect the readers should be aware of the pattern of the book.