This series has taken its place as one of the most important popular- priced editions. The ``Library'' includes only those books which have been put to the test of public opinion and have not been found wanting,--books, in other words, which have come to be regarded as standards in the fields of knowledge,--literature, religion, biography, history, politics, art, economics, sports, sociology, and belles lettres. Together they make the most complete and authoritative works on the several subjects. _Each volume, cloth, 12mo, 50 cents net; postage, 10 cents extra_ Addams--The Spirit of Youth and the City Streets. By JANE ADDAMS. ``Shows such sanity, such breadth and tolerance of mind, and such penetration into the inner meanings of outward phenomena as to make it a book which no one can afford to miss.''--New York Times. Addams--A New Conscience and An Ancient Evil. By JANE ADDAMS. ``A dear, sane, and frank discussion of a problem in civilized society of the greatest importance.'' Bailey--The Country Life Movement in the United States. By L. H. BAILEY. ``. . . clearly thought out, admirably written, and always stimulating in its generalization and in the perspectives it opens.'' Philadelphia Press. Bailey and Hunn--The Practical Garden Book. By L. H. BAILEY AND C. E. HUNN. ``Presents only those facts that have been proved by experience, and which are most capable of application on the farm.''--Los Angeles Express. Campbell--The New Theology. By R. J. CAMPBELL. ``A fine contribution to the better thought of our times written in the spirit of the Master.''--St. Paul Dispatch. Clark--The Care of a House. By T. M. CLARK. ``If the average man knew one-ninth of what Mr. Clark tells him in this book, he would be able to save money every year on repairs, etc.''--Chicago Tribune. <p 3> Conyngton--How to Help: A Manual of Practical Charity. By MARY CONYNGTON. An exceedingly comprehensive work with chapters on the homeless man and woman, care of needy families, and the discussions of the problems of child labor.'' Coolidge -The United States as a World Power. By ARCHIBALD CARY COOLIDGE. ``A work of real distinction . . . which moves the reader to thought.''- The Nation. Croly- The Promise of American Life. BY HERBERT CROLY. ``The most profound and illuminating study of our national conditions which has appeared in many years.''--THEODORE ROOSEVELT. Devine- Misery and Its Causes. By EDWARD T. DEVINE. ``One rarely comes across a book so rich in every page, yet so sound, so logical, and thorough.''--Chicago Tribune. Earle--Home Life in Colonial Days. By ALICE MORSE EARLE. `` A book which throws new light on our early history.'' Ely -Evolution of Industrial Society. By RICHARD T. ELY. ``The benefit of competition and the improvement of the race, municipal ownership, and concentration of wealth are treated in a sane, helpful, and interesting manner.''--Philadelphia Telegraph. Ely -Monopolies and Trusts. By RICHARD T. ELY.