Excerpt from Geometrical Stair Builder, Simplified Fig. 1 is a quadrant; to find the stretch out B C the quadrant, F C the diameter, with the distance F C in the compass, describe two arcs, cutting each other at G, and draw the tangent B E parallel to F C, cutting the quadrant at B; from the point G'r draw a line through C, cutting the tangent at D, then B E is the required length. Fig. 2, another method. A B C is a semicircle; A C the diameter, with the distance A C as a radius; describe two arcs, cutting each other at G, draw the tangent D E through B, extended parallel to A C, the diameter; draw the lines G D and G E through the points A and C, and from the equilateral triangle D E G, any side of which is equal to the semicircle A B C. 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.