NOTES ON MARS. 169 



of Jupiter. Schroter's Mars, for instance, on page 77, fig. 48, of "La 

 Planete Mars'' (1892 edition), tempts one to quote Dante: 



Such would Jove become, if he and Mars 

 Were birds, and changed their phimage. 



We are indebted to M. Flammarion for another line of evidence. 

 He had the happy idea of collecting naked-eye views of the moon by 

 different observers, and in response to his appeal an interesting series 

 appeared in the Bulletin de la Societe Astronomique de France from 

 January to June of last year. The disk of the moon to the unaided 

 eye is about the same size as that of Mars in an average telescope, but 

 the conditions are not quite the same, as naked-eye vision does not 

 admit of straining and misfocusing to the same extent as telescopic. 

 Nevertheless, the study of these drawings is, as M. Flammarion remarks, 

 a lesson on the value to be attached to observations at the limit of visi- 

 bility, and no one would have believed that the same thing could have 

 been represented in so many different ways. The reader may judge 

 for himself by personal examination whether these drawings support 

 Cerulli's theory of the canals. He will not fail to observe a tendency 

 to draw the Seas of Serenity, Tranquillity, Plenty, and Nectar, as two 

 lines more or less parallel, while the Ocean of Tempests is sometimes a 

 narrow, curved line, its eastern border only being seen in contrast with 

 the brilliant limb. Tycho in one instance appears as a very large bright 

 square. 



Whether the optical theory be correct or no, probably no one will 

 deny the wisdom of Signor Cerulli's advice to regard all Martian maps 

 as temporary guides, sure to be modified by further investigation. We 

 may add, however, that to refrain altogether from speculative hypoth- 

 eses would be as unscientific as uninteresting; the sensational theories 

 about Mars have been a stimulus to much excellent work; but the 

 scientist remembers that they are only theories and is prepared to see 

 them dispelled by fuller light. 



III. The Message from Mars.'^ 



Writing from Lowell Observatory, Flagstaff, Ariz., Prof. A. E. 

 Douglass says in the Boston Transcript: The phenomenon on Mars 

 which has given rise to the report of a message from that planet on 

 December 7 of last year was really only a cloud on that planet lighted 

 up by the setting sun. It was a true message, giving us knowledge of 

 Martian climate, but not a message from any intelligent inhabitants. 

 A great number of clouds of this kind have been seen in previous 

 years, but none, I believe, for the last four, and therefore this one, 

 coming as it did in one particular part of the planet, was a matter of 

 great interest, and I telegraphed information about it to the, East, 



1 From Boston Transcript, February 2, 1901. 



