NEW CONCEPTIONS IN SCIENCE 



ceilings might be covered with luminescent sub- 

 stances, so as to make them bright as day. 



Outside, the nights would seem hardly less 

 strange. The atmosphere would be composed 

 chiefly of hydrogen and other light gases argon, 

 krypton, neon, helium, and others whose infini- 

 tesimal presence in the air we breathe has only 

 recently been detected. Could we step out into such 

 an air, we should have a strange feeling, it would 

 offer so little resistance. And as the brilliant au- 

 roras, or northern lights, seem to be associated with 

 the presence of large quantities of hydrogen in the 

 upper strata of the atmosphere, it is not improb- 

 able that in this land of coldest cold the heavens 

 would be almost constantly aglow with these beau- 

 tiful apparitions. 



In such a cold it would be almost impossible to 

 take a photograph, for at the temperature of liquid 

 air light loses eighty per cent, of its chemical 

 power. The forces of cohesion are enormously aug- 

 mented, so that most substances would become 

 as hard almost as quartz or diamond. And they 

 would be proportionally strong. A slender thread 

 of wire, scarce able to bear more than a few ounces 

 at ordinary temperatures, would sustain the weight 

 of a couple of pounds. A stout wire, able now to 

 support some pounds, will, when dipped in liquid 

 air, hold up a ton. 



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