220 WALKS AND TALKS. 



have been, since fire-mist first began to form, a tendency of 

 the liquid particles to coalesce, and this tendency would in- 

 crease with the progress of cooling. A time would arrive 

 when drops thus formed would begin to descend by gravity 

 toward the center of the fire-mist sphere. They are not to be 

 conceived as dropping with accelerated velocity, like bodies 

 falling through space, since within the sphere, the central 

 attraction continually diminishes as the distance from the 

 center diminishes. At the center the attraction is equal in all 

 directions. But the molten liquid began finally to accumu- 

 late at the center. It shaped itself in a globe which grew as 

 the fiery precipitation continued. In the course of time, the 

 greater part of the fire-mist had rained down, and a molten 

 earth stood forth in space, glowing with a white heat, and 

 enveloped in a hot and heterogeneous atmosphere which con- 

 tained all the substances vaporized at the temperature then 

 existing. 



This self-luminous earth was a sun in reference to the 

 moon. The moon had already advanced to a stage corre- 

 sponding with that called habitable, and the light afforded its 

 conceivable inhabitants was twelve times as intense as that re- 

 ceived from the sun assuming the distances the same as at 

 present. The earth was a star, and had long been a star, to 

 the inhabitants, if any, of remote orbs. Perhaps they had 

 descried it with their instruments ; perhaps it had been noted 

 in their catalogues, with latitude and longitude thus and so. 

 The sun was now shedding its superfluous light and heat on a 

 planet which was yet itself a sun. 



The molten earth continued to waste its heat. The ex- 

 posed surface materials, as fast as chilled, sank into the in- 

 terior by their superior density, and hotter materials rose to 

 the surface. There was a circulation between the surface and 

 interior. This prevented any extreme difference in tempera- 

 ture. But some greater reduction was always experienced at 

 the surface. It was at the surface, therefore, that the first 

 solidification took place. At this juncture, the sinking of the 

 coolest portions ceased. Rock-materials, like all others which 



