Excerpt from Micrometer Microscopes After all the intervals have been measured, a length close to the average for one turn of S is selected as a basis of comparison. A multiple of 10 divisions of A is convenient. By simply adding the deviations of the measured five-turn intervals from five times this basis, we compute the progressive corrections at the beginning of each five turns, choosing the point of zero correction at the middle of the screw. T hese corrections will be expressed in divisions of A, and the same unit is retained in all stages of the computation until the end, when the correction curves are read ofi by' a scale which automatically translates into the numbers to be entered in the final table. 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.