PHOTOGRAPH PLATE i Frontispiece Coating a gelatin dry plate by hand. PHOTOGRAPHY By C. E. KENNETH MEES D. Sc DIRECTOR OF RESEARCH AND DEVELOPMENT EASTMAN KODAK. COMPANY ROCHESTER, NEW YORK SECOND EDITION, REVISED NEW YORK THE MACMILLAN COMPANY 1951 Preface to Second Edition THE rapid progress in photography since the first edition of this book was published has made neces sary a revision of some of the chapters. The discovery of the structure of the developed silver image re vealed by the electron microscope has changed and clarified our views as to the process of development. At the same time, the theory of the formation of the latent image has become much more definite. The development of the tripack processes has revolutionized the practice of color photography, which is now in the full tide of an unparalleled ex pansion. Chapters IV, VI, and VIII have accordingly been revised to cover the changes in photographic theory and practice. Rochester, N. Y. December i, 1941 Preface PHOTOGRAPHY is both an art and a science it is an invaluable tool to those working in the other arts and sciences, and there are few activities of civilized man in which it has no part. There are many books on the art of photography, some of which are intended for beginners or for those to whom photography is only an amusement, while others deal in a comprehensive manner with photo graphic technique and its applications. This book, which had its origin in a course of lectures given last Christmas at the Royal Institution in London, is intended to provide a general review of the whole subject of photography written in a simple and popu lar style. The Christmas lectures have been given for more than a century and are intended especially for young people. By custom, the lectures consist largely of experiments and demonstrations, which have neces sarily been replaced in the book by description and illustrations. Photographic science is derived both from physics and from chemistry The preparation of the photo graphic material and its treatment after exposure may Vlll PREFACE be regarded as a branch of applied chemistry the exposure and the relation of that exposure to the photographic image involves the principles of physical optics. But photography has become differentiated from its parent sciences, and there has been developed a science of photography with a literature, a terminol ogy, and an instrumental technique of its own. From the laboratories which are engaged in the study of photographic science will come the future develop ments in the practical art of photography. It has been my fortune to be associated rather closely with the historical development of the subject. In 1901, while a student at the university, my atten tion was directed to the work of Hurter and Driffield, the photographic amateurs whose investigations laid the foundation for all subsequent work on photo graphic sensitometry and from that time, I have been engaged in the study of the science of pho tography. In 1906, I entered the field of pho tographic manufacture by joining the firm of Wratten Wainwright, in which my partners were Mr. F. C. L. Wratten and his son, Mr. S. H. Wratten. F. C. L. Wratten was at first a photographic dealer then he began to manufacture materials, especially collodion emulsion, and he was among the very first makers of gelatin dry plates. Much of the knowledge which I have of the history of that period I received directly from Mr. Wratten. PREFACE IX In 1912, Mr. Eastman invited me to join the East man Kodak Company in Rochester in charge of their research work, and there I have known and worked with the group of men who developed that great industry. While I may expect to watch the develop ment of photography for another score of years, I have known well those who have been responsible for much of its growth in the last sixty. It was this which tempted me to include so much history in this book...
