Back in the 70's of the last century - not so many years ago, after all - photography was in its infancy and but little practiced by the general public. The few professionals who made it their regular business prepared most of their own materials, plates, papers, etc., and the results were frequently very uncertain, as they depended largely upon local conditions, and on the skill and knowledge of the operator. Photography as applied today to the arts and sciences was unheard of. Now, there is hardly a science, industry, or enterprise of any account undertaken that photography, in some form or other, does not enter into. It is invaluable as an aid to research, study, and to the diffusion of knowledge. It has extended its influence far beyond the limits of a popular science, into a world-embracing industry. It is an Art; it is a part of every science. It has revolutionized the art of printing. The magazine and book illustrations, the depicting of current events in the newspapers, the beautiful half-tones, photogravures and three color reproductions that have brought the world's master pieces of Art into our homes, are all the result of photographic process as applied to printing. Its products are the only universal language, understood by all the people of the earth. It has preserved, in facsimile, the world's most valuable manuscripts. In Medicine and Surgery, a greater knowledge of the human body and its component parts has been made possible by X-ray Photography and Photo-Micrography. With the modern dry plates, sensitive to all or any desired colors, photography has become an invaluable ally to the microscope. In Chemistry, Sir William Crookes, by the aid of photospectroscopy and the ortho-chromatic plate, has added a new metal, monium, to the list of elements. In Botany, the kinetoscope has recorded the varying phases of growing plants. The science of Geology has been enriched by photography in many ways, while Meteorology has been advanced by the study of lightning discharges, and the clouds, in photographs. In Astronomy, photographic plates of eclipses of the sun and moon have given us information heretofore unattainable by telescope alone. Nebulae, asteroids, comets and meteors have been studied; their form, detail and conditions have been revealed ; and the astronomer, who could not catch the satellite of Neptune with his telescope, has seen it, with the rings of Saturn, fixed upon his plate. With the spectroscope, photography has helped in the discovery of variable stars, and binaries of the shortest periods have been detected and classified by it. In Schools and Colleges it is a valuable educational appliance. In the Industries, the application of photography is almost unlimited. Its application to the manufacture of tapestries, by furnishing cards for the Jacquard loom, thus putting them within reach of the ordinary man, is well known. As evidence in detecting forgeries, duplicated documents, identifying criminals, and in various other ways, the Courts of all countries accept the photograph. In the late Russo-Japanese war, the camera furnished valuable records. In fact, the application of photography extends to almost every branch of human endeavor.

Its greatest improvements are yet to come. No man or woman, competing seriously for the prizes of life, can afford to be without some knowledge, at least, of the Art-science. Competition, never so sharp as now, demands that all avail themselves of the advantages gained by a scientific and technical training, such as the making of photographs will give. Apart from its value as an aid to success, socially and financially, there is no more delightful and refined pursuit than the making of pictures by photography. The aesthetic element in it lightens the burdens of life and sweetens existence here below for those who appreciate it rightly; and it is for this purpose, and to help others study and master this science, that the "Complete Self-Instructing Library of Practical Photography" is published.