THE MOON 389 



normally empty. I say normally empty advisedly, for 

 the reason that during the hot season, as we can see to- 

 day, a good deal of the snow naturally thaws again and 

 trickles down into the lowest places, forming there black 

 pools which contrast vividly with the scant vestiges of 

 snow that may be found in these recurrently flooded re- 

 gions. Between the blackness of such pools, however, 

 and driven snow, there are, of course, all gradations of 

 white though no colors to be seen. These diverse 

 shades are due to one, or to the combination, of two 

 causes ; first, to the soaking of low-lying snow as a result 

 of thawing, and, second, to a seaming and corrugating of 

 other snow surfaces, especially on slopes, by irregular 

 thawing, slipping, and settling ; the dense shadows of the 

 ridges in the furrows marring the general brightness. 



It would be unreasonable for us to expect to find on 

 our ocean beds, could they be revealed to our eyes, the 

 same perfection and profuse diversity of configurations 

 that our land surfaces exhibit, and the same thing is true 

 of the lunar maria. These tell us just what they are. 

 The " ruined" mounds, craters, and other structures we 

 there see are merely the abortive efforts of the Ice King 

 when his supply of raw material had about given out. 

 Apropos of this, I cannot forbear to quote the lucid im- 

 pressions of an amateur astronomer, the late Mr. John A. 

 Cook, as set forth in Popular Astronomy (No. 235) : 



For more than thirty years I have been studying and observing 

 the Lunar surface in an amateurish way, using instruments rang- 

 ing in size from two to ten inches, and have arrived at conclusions 

 at variance with those, so far as I know, held by the great selen- 

 ographers, living and dead, regarding the above mentioned fea- 

 tures. 



We find them scattered about over the floors and shores of 

 the Ocean and seas. When found fully down on the sea floor 

 they often present but the merest trace of a ring. Those on the 

 shore will show that part down in the sea destroyed, while that 

 portion of the crater on higher ground is intact. 



Writers speak of them as Ruined walls, Submerged walls, 

 Melted walls, and often as destroyed by some unknown cause. 



I have searched the works of Neison, Pickering, Elgar, Lohr- 

 mann, Fauth, Nasmyth & Carpenter, Serviss and a host of other 

 more general works to find if some one would not suggest water 



