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X. 
ON THE ORIGIN OF THE CANALS OF MARS. By J. JOLY, M.A., B.A.L., 
Sc. D., F.R.S., Hon. Sec. Royal Dublin Society. 
(Puates XV. anp XVI.) 
[Read January 20, anp Marcu 24, 1897. ] 
THE confirmation which Professor Schiaparelli’s observations have received in the 
careful study of Mars’ surface made by Mr. Percival Lowell and his colleagues, 
Mr. D. EK. Douglass and Professor W. H. Pickering, has justifiably raised the 
problem of the origin of the ‘‘ canals” of Mars to a level of much interest and 
serious importance. Our present knowledge of the appearance of the Martian 
surface certainly justifies speculation as to the cause and nature of that appearance, 
so unlike anything with which observations, either upon our own Earth, or upon 
other heavenly bodies, has made us acquainted with. The double lines, and the 
strange doubling of these lines, first observed by Schiaparelli, have been fully 
substantiated, not only by the observers of Flagstaff Observatory, but by many 
others observing under favourable conditions. Mr. Douglass has added the 
important observation that the curved lines traverse the dark areas as well as the 
light areas of the planet’s surface. The general course and character of the curves 
appear the same in the observations of Lowell and Schiaparelli, where these 
observations overlap. The presence of peculiar round dark patches upon the 
lines marking their points of meeting and crossing, although, as might be 
expected from the better conditions of observations at an altitude of 7000 feet in 
Arizona, more definite in Mr. Lowell’s observations, is yet substantiated in 
Schiaparell’s maps. The curved rifts crossing the polar snows have been 
observed by many independent observers. 
Finally, it will be found, further on in this Paper, that the curvature of the 
lines, mapped by Lowell, agrees, in a remarkable manner, with a certain theory of 
the common mode of origin of these lines—a mode of origin which would at once 
account for their curvature and for their peculiar appearance as double or even 
TRANS. ROY. DUB. SOC., N.S. VOL. VI., PART X. 2P 
