The following pages have been written for the general reader. The controversies over the interpretation of the curious markings of Mars and the wide divergence of opinion as to their nature first turned my attention to the matter. The question of intelligence in other worlds is of perennial interest to everyone, and that question may possibly be settled by an unprejudiced study of our neighboring planet Mars. Knowing the many analogies between Mars and the Earth, we are justified in asking what conditions really exist in Mars. Instead of flouting at every attempt to interpret the various and complicated markings of its surface, we should soberly consider any rational explanation of these enigmas from the postulate that the two spheres, so near together in space, cannot be so far apart physically, and from the fact that as intelligence is broadly modifying the appearance of the surface of the Earth, a similar intelligence may also be marking the face of Mars.

A student familiar with a general knowledge of the heavens, a fair acquaintance with the surface features of the Earth, with an appreciation of the doctrine of probabilities, and capable of estimating the value of evidence, is quite as well equipped to examine and discuss the nature of the markings of Mars as the astronomer. If, furthermore, he is gifted with imagination and is free from all prejudice in the matter, he may have a slight advantage. Astronomers are probably the most exact of all students as to their facts, and in this discussion there is no attempt to introduce evidence they do not supply, as the frequent quotations from their writings will show.

Having studied Mars through nearly one presentation of the planet with the great refractor at the Lowell Observatory, what I saw with my own eyes, uninfluenced by what others saw, will be presented in a short chapter at the end of this book.

I wish to express my obligations to Professor Percival Lowell for the privileges of his observatory, for many of the illustrations in this book, and for his unbounded hospitality during my visit to Flagstaff. I am also deeply indebted to Mr. Russell Robb for valuable assistance during the preparation of the manuscript.

E. S. M.

Salem, Massachusetts,
October, 1906.