The Circle of Knowledge: A Classified, Simplified, Visualized Book of Answers

ESSENTIAL FACTS OF EVERYDAY INTEREST IN NATURE, GEOGRAPHY, HISTORY, TRAVEL, GOVERNMENT, SCIENCE, INVENTION, EDUCATION, LANGUAGE, LITERATURE, FINE ARTS, PHILOSOPHY, RELIGION, INDUSTRY, BIOGRAPHY, HUMAN CULTURE, AND UNIVERSAL PROGRESS
Easy to Read; Easy to Understand; Easy to Retain
EDITOR-IN-CHIEF HENRY W. RUOFF, M.A., Litt.D., D.C.L. Editor of “The Century Book of Facts,” “The Capitals of the World,” “Leaders of Men,” “The Standard Dictionary of Facts,” “Masters of Achievement,” “The Volume Library,” “The Human Interest Library,” Etc.
NUMEROUS TEXT ILLUSTRATIONS, MAPS TABLES, DUOTONE AND COLOR PLATES
Exclusive Publishers for Canada and Newfoundland: THE JOHN A. HERTEL CO., Ltd. TORONTO, ONTARIO
THE STANDARD PUBLICATION COMPANY BOSTON · WASHINGTON · CHICAGO 1917
Copyright, 1916, by THE STANDARD PUBLICATION COMPANY
Copyright, 1917, by THE STANDARD PUBLICATION COMPANY
All Rights Reserved

All books that are really worth while may be divided into four classes: first, books of information ; second, books of inspiration ; third, books of entertainment ; fourth, books of excitement . By far the most important and practical of these classes is the first. The next in importance is the second; while rather trivial importance attaches to the third and fourth.
THE CIRCLE OF KNOWLEDGE preëminently belongs to the first; but it is also designed to be both inspiring and entertaining. In its methods of presentation and in its editorship it typifies the modern, progressive spirit. Behind it lies a quarter of a century of successful editorial experience in selecting, adapting, and translating from highly technical treatises into simple, clear, understandable language the essentials as well as important sidelights of human knowledge. Its purpose is to answer the why, who, what, when, where, how, of the vast majority of inquiring minds, both young and mature, and to stimulate them to still further questionings. For it is only through this self-questioning process of the active mind that individual progress is possible.