Excerpt from The Telescope-Mirror-Scale Method Adjustments and Tests<br><br>IN the telescope-mirror-scale method for measuring small angles, an illusory estimate of the accuracy attained may easily arise through inattention to the requisite adjustments, tests, and corrections. Yet an adequate and well-ordered presentation of them is not to be found. Partial statements are given in text-books on manipulation, but Czer mak2 alone has given a discussion approaching completeness. Even this omits some essential points, and moreover is not arranged in a manner to lend itself readily to the practice of the method.<br><br>The following presentation of the subject is designed for the observer who would put the method into direct service for obtaining measurements of a Specified or of a determinate accuracy. It there fore not only discusses the several sources of error, but describes the various adjustments and tests in the sequence in which they should ordinarily be made, and gives a numerical measure of the closeness with which each must be carried out to secure a specified precision in the result. Some remarks on the selection of instruments are appended.<br><br>About the Publisher<br><br>Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com<br><br>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.