68 



This opiiosirion w.-is not iiciirly so f:i\(ir;il)l(> to tlic observation (tf sur- 

 face cliaracferisties as some in tlie past, as .Mars and rlie <'artli were so 

 situated tliat at the time ol' opposition INIars was at his greatest distance 

 fi-(un tlie sun, wiiile tin' earth was at its least distance, thus making the 

 distance between .Mars and the eartli almost a maximum. So great is the 

 eccentricity of the planet's orbit that this distance at opposition may vary 

 from thirty-live million miles to over si.xty-two million miles. In this 

 ease it was near the latter limit, the nearest approach being on the 22d 

 of F'ebruary. 



This oi(posiri(jn was also somewhat unfavorable if we compare results 

 with those ol)tained in 181)2 and ]s;)4. in that the southern pole of the 

 l>lanet which was at that time turned toward us. at this opposition was 

 turned away from us. 



The large dark areas on the planet are mainly in the southern hemi- 

 sphere and are the most easily seen of anything on the surface except the 

 polar cap. It will be observed that there are also large dark areas in the 

 northern hemisphere, but these, for the most part, ai-e very changeable, 

 both in size and shape and intensity, indicating probably that they are 

 really water and that the change is purely seasonal in character. One of 

 the most conspicuous markings on the planet at the time of opposition was 

 the great polar ice cap. It will be observed that the early drawings all 

 represent this feature as large, and the brilliant white color made it stand 

 out in a very conspicuous manner against the yellow and red of the rest 

 of the surface, while, toward the end of the series, the cap has diminished 

 in size so as to be easily overlooked altogether. It will also be observed 

 that the ice cap is represented Avith a dark fringe surrounding it. that 

 this fringe follows the edge of the cap as it melts away, and that at the 

 same time the dark areas near this pole become much enlarged and much 

 more intense in conti-ast with tlie liriglit yellow of the disk. This tends 

 to show that these dark patches are really Avater and as the polar snows 

 melt, the water runs out over the comparatively level surface in great 

 pools. 



A few of the numerous so-called canals are shown. As to .lust the 

 character and origin of these objects there has been a great deal of dis- 

 cussion. Their reality was even questioned for some time after their dis- 

 covery, but of that there can now be no doubt at all. These canals were 

 first seen by Schiaparelli in 1877, and from that time till the present they 

 have been a constant source of perplexity. The same observer shortly 



