Excerpt from A Treatise on Photography The numerous advances in the art of Photography have made it incumbent on the author to make a thorough revision of the previous editions of this work. This has not only necessitated the addition of new matter, but also the excision of some which it was felt might be omitted without detriment to the completeness of the subject. The additions have, however, considerably overbalanced the excisions, with the result that the pages have been considerably increased in number. The aim of the author has been to give a rational explanation Of most of the different phenomena to be met with in Photography, and at the same time to give sufficient practical directions to enable the student to produce a picture which should be technically good, and also to show how Photography may be made an aid to research. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.