Excerpt from The Theory of Modern Optical Instruments: A Reference Book for Physicists, Manufacturers of Optical Instruments, and for Officers in the Army and Navy The committee of the Privy Council for scientific and industrial research realised at an early stage the necessity for rendering assistance to the optical instrument making industry, and it was suggested by their advisory council, assisted by the standing committee on glass and optical instruments, that one way of doing this lay in the translation and publication of certain foreign works. One of those recommended was Dr. Gleichen's "Die theories der modernen optischen instrumente," and the standing committee, in looking for a suitable translator, found that Messrs. Emsley and Swaine, two men of science associated with the firm of Messrs. Barr and Stroud, ahd already begun to translate this work. These gentlemen agreed to complete the English version for the Committee of Council, who were thus enabled to issue a work which, because of its special character, is likely to be of particular value to students of this subject. The volume was prepared under the direction of an editorial committee to whom, including especially the chairman, Mr. E. B. Knobel, F.R.A.S., the committee of council are much indebted. The committee were not asked to review the terminology and the use of symbols adopted by the translators, for this, by raising the whole question of nomenclature in optics, would not only have caused a serious delay in the appearance of the work, but would have raised difficult and far-reaching problems which could not at the moment receive attention they deserve. The text of the original was closely followed, with certain exceptions, to which reference is made in the Translator's preface. The first edition of this work included an appendix by the translators on the subject of rangefinders, which it is understood proved valuable. Further information has, however, now been obtained with regard to other optical instruments, and the committee of council have decided to publish it, with the appendix on rangefinders, in a separate volume. The committee of council are indebted to Messrs. Barr & Stroud for the loan of blocks representing views in Rangefinders. 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.

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This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Practical guide shows how to set up working models of telescopes, microscopes, photographic lenses and projecting systems; how to conduct experiments for determining accuracy, resolving power, more. 234 diagrams.