Includes "28 Heliotype illustrations from a number of methods, each designed to highlight various applications of the process ... This book was prepared in conjunction with Osgood's display at the Centennial in Philadelphia. All of the plates are from prior publications and Edwards wrote the description of the process. This is one of the most lavish presentations executed by a printing firm as a form of advertisement and only Osgood would have such funds available. This book is one of the most significant photomechanical display books in the United States in the nineteenth-century."--Hanson Collection catalog, p. 55.