“It is not only as an astronomer but as a writer that Professor Lowell charms the reader in this work. The beguilement of the theme is well matched by the grace and literary finish of the style in which it is presented. The subject is one to beget enthusiasm in its advocates, and the author certainly is not devoid of it. The warmth and earnestness of the true lover of his theme shine through the entire work so that in its whole style and illustrations it is a charming production.”—_St. Louis Globe Democrat._ “Mr. Lowell approaches the subject by outlining the now generally accepted theory of the formation of planets and the solar system. He describes the stages in the life history of a planet three of which are illustrated in the present state of the earth, Mars, and the moon. He tells what conditions we would expect to find on a planet in what we may call the Martian age, and proceeds to show how the facts revealed by observation square with the theories. The book is fascinatingly readable.”—_The Outlook._ “So attractive are the style and the illustrations that the work will doubtless draw the attention of many new readers to its fascinating subject. Professor Lowell has fairly preëmpted that portion of the field of astronomy which interests the widest readers, for there is no doubt that speculation regarding the possibility of life on other planets than our own has a peculiar attraction for the average human mind.... For the convenience of the non-technical reader, the body of the book has been made as simple and understandable as possible.”—_Philadelphia Press._ PUBLISHED BY THE MACMILLAN COMPANY 64-66 Fifth Avenue, New York End of Project Gutenberg's The Evolution of Worlds, by Percival Lowell