To give it its full value, therefore, an index became obviously necessary--and no ordinary index. Its aim must be to anticipate every possible question with which a reader might approach the past, and direct him to the answer. Even, it might be, he would want details more elaborate than we give. If so, we must direct him where to find them. Professional index-makers were therefore summoned to our help, a complete and readable chronology was appended to each volume, and the final volume of the series was turned over to the indexers entirely. We believe their work will prove not the least valuable feature of the whole. Briefly, the Index Volume contains: 1. A complete list of the Great Events of the world's history. Opposite each event are given the date, the name of the author and standard work from which our account is selected, and a number of references to other works and to a short discussion of these in our Bibliography. Thus the reader may pursue an extended course of study on each particular event. 2. A bibliography of the best general histories of ancient, mediaeval, and modern times, and of important political, religious, and educational movements; also a bibliography of the best historical works dealing with each nation, and arranged under the following subdivisions: (_a_) The general history of the nation; (_b_) special periods in its career; (_c_) the descriptions of the people, their civilization and institutions. On each work thus mentioned there is a critical comment with suggestions to readers. This bibliography is designed chiefly for those who desire to pursue more extended courses of reading, and it offers them the experience and guidance of those who have preceded them on their special field. 3. A classified index of famous historic characters. The names are grouped under such headings as "Rulers, Statesmen, and Patriots," "Famous Women," "Military and Naval Commanders," "Philosophers and Teachers," "Religious Leaders," etc. Under each person's name is given a biographical chronology of his career, showing every important event in which he played a part, together with the date of the event, and the volume and page of this series where a full account of it may be found. This plan provides a new and very valuable means of reading the biography of any noted personage, one of the great advantages being that the accounts of the various events in his life are not all in the language of the same author, not written by a man anxious to bring out the importance of his special hero. The writers are mainly interested in the event, and show the hero only in his true and unexaggerated relation to it. Under each name will also be found references to such further authorities on the biography of the personage as may be consulted with profit by those students and scholars who wish to pursue an exhaustive study of his career.