VARIABLE STARS. 247 



radiation of heat from the deeper strata of the earth through 

 open fissures, and through unfilled veins the greater power 

 of electric currents a very different distribution of sea and 

 land; may also, in the earliest epochs of the earth's 

 existence, have rendered the diffusion of heat independent of 

 latitude ; that is to say, of position relatively to a central 

 body. Cosmical considerations must not be limited merely 

 to astrognostic relations. 



