MARS AS A WORLD. l6j 



It is shown in Fig. 14 as the dark pointed region extend- 

 ing towards the north pole. 



Around the north pole, as around the south, is also to 

 be found the accumulation of white material which so 

 irresistibly reminds us of snow. I have often been struck, 

 when observing Mars with the 12-inch refractor of the 

 Dunsink Observatory, with the extremely sharp boundary 

 line by which this white region is marked off from the 

 body of the planet. 



I must now discuss another discovery, the result of the 

 acute observations of Schiaparelli, the director of the 

 Milan Observatory, to whose labours much of our know- 

 ledge of the topography of the planet is due. 



In September, 1877, when Mars occupied that particular 

 situation relatively to the earth in which the distance 

 between the two globes was almost at its lowest point, 

 and when, consequently, the apparent magnitude of the 

 planet attained its highest value, Professor Schiaparelli, 

 availing himself of the clear atmosphere in which his 

 observatory was situated, made a remarkable observation 

 on the planet. He showed that the regions heretofore 

 spoken of as continents appeared to be intersected by dark 

 streaks, which must have been about sixty miles wide, 

 and which often attained a length of thousands of miles. 

 During the opposition of 1881-1882, Schiaparelli again 

 recognised the presence of the canals, but on this occasion 

 it would seem that a very extraordinary phenomenon was 

 perceived. Several of the canals were observed to be 

 double, that is to say, there were a pair of canals seen 

 separated by an interval of two hundred miles or more, 

 and running parallel to each other throughout their whole 



