This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced

This is a reproduction of a book published before 1923. This book may have occasional imperfections such as missing or blurred pages, poor pictures, errant mark

Sir James Alfred Ewing (1855-1935) was a Scottish engineer, physicist and cryptographer. First published in 1926, as the fourth edition of an 1894 original, thi