PREFACE THAT at least an elementary knowledge of the subject of build- ing stones and clay products is of importance to the architect few people will deny, since familiarity with their properties, durability, and, in the case of clay products, their methods of manufacture will enable him to select and use these materials more intelligently. At the same time, the preparation of an elementary work on the subject is not free from difficulties, for the reason that most architects have but a limited knowledge of geology and ceramic technology. The author has, therefore, attempted to state facts and explanations as simply as possible, and as a further aid in this direction has included a glossary at the end of the book. The general arrangement of the book follows the course of lectures given each year to the students in the College of Archi- tecture of Cornell University, and it has been the encouraging reception which these received that has led the author to give them to the public. Thework is notintended asan exhaustive treatise, but, in stead, aims to give simply the fundamentally important facts. It is therefore, beyond the scope of the book to take up any but the more important occurrences of building stone, and those who desire detailed information on this point will consult our standard American work, Stones for Building and Decora- tion by G. P. Merrill. Since the architect often desires to know how extensively and for what purposes the different building stones have been used, an attempt has been made to give a list of structures in which the more important ones at least have been placed. The author wishes to acknowledge here assistance and advice received from many persons in the preparation of the work iii 263614 IV PREFACE includingMr. E. C. Stover, Trenton Potteries Co., Trenton, N. J. Mr. W. H. Gorsline, Rochester, N. Y. Prof. C. W. Parmalee, Rutgers College, New Brunswick, N. J. Acknowledgments for cuts or photos loaned are made under the respective illustrations. CORNELL UNIVERSITY, ITHACA, N. Y. June, 1912. HEINRICH RIES. CONTENTS. PREFACE iii CONTENTS v LIST OF PLATES , PAGE jd LIST OF FIGURES xv INDEX 401 PART I. BUILDING STONES. CHAPTER I... --This text refers to an alternate Paperback edition.