Excerpt from Modern Optical Instruments And Their Construction The strides made in the construction of optical instru ments has led me to compile the following chapters relating to the subject, which will, no doubt, prove inter esting to many. I shall endeavour to explain the use of the different instruments for their especial purposes, and also their construction, and the object of each part; but, before starting, it would be as well to examine Nature's optical instrument, and having seen the construction of that, we shall then see how many of the optical instru ments are approximately the same in their construction. 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.