Excerpt from Shades and Shadows and Perspective: A Text-Book Based on the Principles of Descriptive Geometry The aim of this treatise is to present through a knowledge of descriptive geometry, those principles which are fundamental in the solution of both theoretical and practical problems and, by a formulation of these principles, to arrive at and thus place upon a mathematical basis those rules and formulas which are commonly used in practice. The method of presentation, which has been developed and tested during fifteen years of experience in the class room, seeks to introduce and substantiate each principle by reference to the simplest form of magnitude. For this reason no attempt has been made at either elaborate or artistic drawings, as these belong rather to the field of application. 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.