234 THE BORDERLAND OF SCIENCE. 



interval between his eyes should equal the distance be- 

 tween the place where the earth stood when one view was 

 taken, and that to which it would have been removed 

 (the moon being regarded as fixed) to get the other. 

 Nothing can surpass the impression of real corporeal 

 form thus conveyed by some of these pictures as taken 

 by Dr. De la Eue with his powerful reflector, the 

 production of which (as a step in some sort taken by 

 man outside of the planet he inhabits) is one of the 

 most remarkable and unexpected triumphs of scientific 

 art.' 



Both the measurement and the simple contemplation 

 of the stereoscopic pairs of lunar pictures appearing to 

 indicate the same result, we may proceed to inquire 

 under what circumstances that result may have been 

 brought about. The true explanation can scarcely fail 

 to be a singular one, whatever it may be ; so that if 

 we are led to a view which appears sensational, this 

 must not be regarded as a surprising circumstance. 



Now let it be noted that, whatever ideas we may 

 form as to the past condition of our earth and the other 

 members of the solar system, we can scarcely refuse to 

 admit the general theory that in long-past ages every 

 one of these globes was in a condition of intense heat. 

 That our earth was formerly liquefied by intensity of 

 heat is the opinion of all who have carefully studied 

 her surface ; and there are few men of science who do 

 not, after examining the evidence, conform to the 

 theory of Meyer, that the earth was formerly in a 



