8 



free by denudations, faults and fractures, is principally 

 taken up by water in its fluid and vaporous form, and 

 conserved by water in the form of clouds. 



(4) The surface temperatures of such a spheroid 

 must be practically independent of exterior sources of 

 heat until the greater portion of the water surrounding 

 it be reduced to its point of maximum density or con- 

 verted into ice, and that prior to this stage of its cli- 

 matic evolution, its surface temperatures are practically 

 controlled by interior (or planetary) heat, and are prac- 

 tically independent of latitude; and are therefore inde- 

 pendent of the temperature to which the outer surface 

 of the cloud sphere may be exposed. The effect of 

 variations in exterior heat being mainly to increase or 

 decrease the duration of the interior supply, and to ex- 

 pand or contract the sphere of cloud condensation. 

 The principal function of exterior heat, prior to the 

 chilling of the oceans, being conservative or to replace 

 in part the heat lost by radiation from the cold outer 

 surface of the cloud sphere. 



(5) That until the exhaustion of the available inter- 

 nal heat supply, outside of a crust of low conductive 

 power, the surface temperatures of the spheroid must be 

 nearly uniform from pole to pole, varying only with 

 elevation above sea level, or from local causes, such as 

 the influence of lava outbursts upon the areas to the lee- 

 ward of such outbursts. And that a series of uniform 

 climates must prevail independent of latitude, and 

 gradually decreasing in temperature as the spheroid 

 loses heat. 



(6) That the low specific heat of land areas permits 

 them to cool more rapidly and to reach glacial tempera- 

 tures before the oceans are reduced approximately to the 

 point of maximum density, and consequently that snow 



