Excerpt from The Six-Chord SpiralWhen not given in the ordinary field tables, they may be found by mentally subtracting the natural cosine of the given angle from 9999 working from left to right, and calling the last decimal used 10.To find the angle corresponding to a given natural versed sine, subtract the latter from 9999 as above. The remainder will be the natural cosine of the required angle.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.