Excerpt from Practical Mathematics: Summary of Six Lectures Delivered to Working Men by Professor John Perry, D.Sc., F. R. S., At the Museum of Practical Geology, Jermyn Street, February and March, 1899, With Certain Exercises Supposed to Be Worked After Every Lecture When I was at school the mean distance from the earth to the sun was stated as miles. I wonder why furlongs and inches were not mentioned. The best know ledge we now have of this distance is that it is not greater than 93 nor less than 925 millions of miles. 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.