342 Remarks on the Planets Jupiter and Saturn. 



and condition of the lunar surface, I made some remarks on 

 the principle, which, as it appears to me, gives the law to 

 the comparative rate of cooling of the planets, namely, that 

 while the heat-retaining quality was due to the mass of the 

 planet, the heat-dispensing property was governed by its 

 surface ; and as the former increases as the cube of the dia- 

 meter of the planet, while the latter increases only as the 

 square of its diameter, we thus find that the length of time 

 which would be required by such enormous planets as Jupiter 

 and Saturn to cool down from the original molten and in- 

 candescent condition to such a temperature as would be fitted 

 to permit their oceanic matter to permanently descend and 

 rest upon their surface, would be vastly longer than in the 

 case of such a comparatively small planet as the earth. 



Adopting the results which geological research has so 

 clearly established as respects the original molten condition 

 of the earth, as our guide to a knowledge of the condition 

 of all the other planets, it appears to me that we may in this 

 way be led to some very remarkable and interesting conclu- 

 sions in reference to the probable present condition of such 

 enormous planets as Jupiter and Saturn, tending to explain 

 certain phenomena in respect to their aspect. 



Assuming as established the original molten condition of 

 the earth, and going very far back into the remote and pri- 

 mitive periods of the earth's geological history, we may find 

 glimpses of the cause of those tremendous deluges, of which 

 geological phenomena afford such striking evidence,* and by 



* The deluges here alluded to arc quite distinct from those which have so fre- 

 quently, during various periods of the earth's geological history, swept over 

 vast portions of its surface, and of whose tremendous violence we have such 

 clear evidence, in the denudation of the hardest rocks, the debris of which has 

 yielded the material of nearly every sedimentary formation, from the period of 

 the old red sandstone formation upwards. 



These vast and often repeated deluges I consider to have resulted from mighty 

 incursions of the ocean, over vast continents, till then forming the dry portion of 

 the earth's surface, hut which (hy the retreat of the earth's substance from be- 

 low, resulting from the progressive contraction, consequent on the gradual 

 cooling of the sub-surface matter) must have again and again permitted ex- 

 tensive portions of the solid cru6t of the earth to suddenly crush down, like an 



