Excerpt from Photographer's Pocket Reference-Book and Dictionary: An Alphabetically Arranged Collection of Practically Important Hints on the Construction of the Gallery, Selection and Trial of Lenses and Chemicals, Approved Formulæ for the Different Photographic Processes, Tables of Weights and Measures, Rules for AvoiIn this little work numerous notices have been embodied which have not been published heretofore, and which I have collected during my long practical career.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis 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.