ISO THE BORDERLAND OF SCIENCE. 



leaving the features of the rest of the globe concealed 

 from view under their snow-white veil. 



Those who have seen Mars under good telescopic 

 6 power ' will at once recognize the exact agreement 

 between this hypothetical process and the actual ap- 

 pearance of the planet. All round the border of the 

 disc there is a white light completely concealing all 

 the features of the Martian continents and oceans. Of 

 this peculiarity no satisfactory explanation has hitherto 

 been advanced. I have, indeed, shown how the pecu- 

 liarity would present itself if the Martian atmosphere 

 were loaded with rounded clouds resembling our summer 

 woolpack clouds ; but it is a little difficult to believe that 

 all over Mars such clouds as these are prevalent. More- 

 over, it is to be noticed that these woolpack clouds are 

 morning and forenoon phenomena on our earth ; towards 

 noon they either vanish or become modified in shape, 

 and as evening approaches the clouds ordinarily assume 

 a totally different aspect, being extended in long flat 

 sheets, the stratus cloud of the meteorologist. Even 

 when rounded clouds are present in the evening sky, 

 they are not the separate small white clouds absolutely 

 essential for the theory formerly advanced by me ; but 

 the great heavy cloud is seen 



That rises upward always higher, 



And onward drags a labouring breast, 

 And topples round the dreary west 



A looming bastion fringed with fire. 



According to the views here suggested we have as the 

 principal feature of Martian meteorology the melting 



