98 LIGHT SCIENCE FOR LEISURE HOURS. 



ours. And these, observing the earth's polar snow-caps, 

 must be led to several important conclusions respecting 

 physical relations here. 



It is, indeed, rather a singular fact to contemplate, 

 that ex-terrestrial observers, such as these, may know 

 much more than we ourselves do respecting those 

 mysterious regions which lie close around the two poles. 

 Their eyes may have rested on spots which, with all our 

 endeavours, we have hitherto failed to reach. Whether, 

 as some have thought, the arctic pole is in summer 

 surrounded by a wide and tide-swayed ocean ; whether 

 there lies around the antarctic pole a wide continent 

 bespread with volcanic mountains larger and more 

 energetic than the two burning cones which Ross found 

 on the outskirts of this desolate region ; or whether 

 the habitudes prevailing near either pole are wholly dif- 

 ferent from those suggested by geographers and voyagers 

 such questions as these might possibly be resolved 

 at once, could our astronomers take their stand on some 

 neighbouring planet, and direct the searching power of 

 their telescopes upon this terrestrial orb. For this is 

 one of those cases referred to by Humboldt, when he 

 .said that there are circumstances under which man is 

 able to learn more respecting objects millions of miles 

 away from him than respecting the very globe which he 

 inhabits. 



If we take a terrestrial globe, and examine the actual 

 region near the North Pole which has as yet remained 

 unvisited by man, it will be found to be far smaller than 

 many imagine. In nearly all maps the requirements 



