CHAPTER XVII 



THE vast dark thing that looked like a poised crow of unholy 

 dimensions. Assuming that I shall ever have any readers, let 

 him, or both of them, if I shall ever have such popularity as that, 

 note how dim that bold black datum is at the distance of only two 

 chapters. 



The question: 



Was it a thing or the shadow of a thing? 



Acceptance either way calls not for mere revision but revolution 

 in the science of astronomy. But the dimness of the datum of only 

 two chapters ago. The carved stone disk of Tarbes, and the rain 

 that fell every afternoon for twenty if I haven't forgotten, myself, 

 whether it was twenty- three or twenty-five days! upon one small 

 area. We are all Thomsons, with brains that have smooth and 

 slippery, though corrugated, surfaces or that all intellection is asso- 

 ciative or that we remember that which correlates with a domi- 

 nant and a few chapters go by, and there's scarcely an impression 

 that hasn't slid off our smooth and slippery brains, of Leverrier and 

 the "planet Vulcan." There are two ways by which irreconcilables 

 can be remembered if they can be correlated in a system more 

 nearly real than the system that rejects them and by repetition 

 and repetition and repetition. 



Vast black thing like a crow poised over the moon. 



The datum is so important to us, because it enforces, in another 

 field, our acceptance that dark bodies of planetary size traverse this 

 solar system. 



Our position: 



That the things have been seen: 



Also that their shadows have been seen. 



Vast black thing poised like a crow over the moon. So far it is 

 a single instance. By a single instance, we mean the negligible. 



In Popular Science, 34-158, Serviss tells of a shadow that Schroe- 

 ter saw, in 1788, in the lunar Alps. First he saw a light. But then, 

 when this region was illuminated, he saw a round shadow where the 

 light had been. 



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