Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The present book is in reality little more than an en largement of Professor Ames' book, the principal changes being in the increased number of exercises. Additional illustrations have been put in and a few chapters added. In this work of revision and enlargement the author desires to express his indebtedness to Professor John B. Peddle of the Rose Polytechnic Institute.