ABSTRACT
The book is written for those, young and old, who wish to have a non-technical account of the great scientific and material triumphs which man has achieved and is achieving in their own day; and it seemed desirable to give first place to those theories, facts, and accomplishments which are now exercising the greatest influence upon human life. For science exists not so much to tickle the intelligences of the few as to brighten the lot of the many.
