Excerpt from The Mechanic's and Student's Guide in the Designing and Construction of General Machine Gearing: As Eccentrics, Screws, Toothed Wheels, Etc;, And the Drawing of Rectilineal and Curved Surfaces; With Practical Rules and Details Fig. 3. To Construct a Heart Motion - Before proceeding with the construction of this kind of curve, it may be observed that it is also a double eccentrical and symmetrical curve, producing a uniform and a straight motion, of which the length or stroke would be from D to D', and in imagining C as the centre of the shaft, the point D would have to traverse to D' in each half revolution. After the stroke has been determined, draw inner and outer circles, here A D, and D' F E G; divide the same into any number of parts, say 24, and draw radial lines, I, 2, 3, 4, etc.; proceed in dividing D to D' in half the number of parts to those on the circumference, here 12, and draw semicircles through them, and at intersections of radial lines, I, 2, 3, 4, etc., will be the different points for the curve of the heart motion. 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.