AND ITS INHABITANTS 35 



itself, even in its molten stage, an envelope of water in the 

 form of a deep and heavy atmosphere of water-gas. Such an 

 envelope, including also an abundance of carbon dioxide and 

 carbon monoxide, formed an effective thermal blanket, pre- 

 venting a precipitous chilling and freezing at the surface of 

 the ocean of molten rock. 



The effectiveness of the blanket depended upon the pecu- 

 liarity of both water-gas and carbon dioxide in being opaque 

 to the slow vibrations of dark heat, absorbing these near 

 the bottom of the primitive atmosphere and reradiating them 

 from higher levels as long, slow heat waves. Strong convec- 

 tion currents carried up these heated gases from the super- 

 heated base to the higher levels of the atmosphere. There the 

 chilling condensed the water-vapor into a thick and universal 

 canopy of cloud, boiling up like thunder-heads from below, 

 shedding continuously a downpour of acid rain, rain dissipated 

 again into vapor as fast as the drops fell into the deeper and 

 hotter strata of the atmosphere. The intensity of the vertical 

 convection maintained a high electric tension. Incessant 

 flashes of lightning linked as with living, fiery tentacles the 

 cloudy heavens to the lurid molten earth. Tremendous re- 

 verberations of thunder, unsensed by mortal ears, shook the 

 atmosphere in the worldwide primeval storm. 



The sunlight of the Primordial Era illumined and was 

 reflected from the outer side of the mantle of cloud. The 

 planet shone brilliantly by this reflected light, having an ex- 

 ternal appearance similar to that which Jupiter and Saturn 

 still possess. Above the zone of cloud the carbon dioxide and 

 other gases, with very minor amounts of water-vapor, ex- 

 tended with diminishing density as an upper transparent 

 envelope. 



During the more rapid growth-stages the molecular and 

 dust-like matter swept up by the earth settled like a never 

 ceasing cloud of volcanic ash. The planetesimals of sand and 



