THE ORGANISM AS A MECHANISM 57 



and stellar radiation. Stellar radiation is minute, the 

 absolute temperature of cosmic space (or ether) being 

 about - 263 ° C. The absolute temperature of the earth 

 is about +17° C, so that it radiates off more heat into 

 space (other than that represented by the sun) than 

 it receives. All energy-transformations on the earth 

 (except tidal effects, and energy-conduction from 

 the heated core, and possibly radio-active effects) are 

 transformations of this solar energy received by 

 radiation. We see these in oceanic and atmospheric 

 circulations (currents, winds, rainfall, etc.). We see 

 them also in the transformations of the chemical 

 potential energy of coal and other products of life — 

 products in which the contained potential energy has 

 been absorbed from solar radiation. 



Let us follow the transformations of this energy. 

 Oceanic currents transport heat from the equatorial 

 sea-areas to the colder temperate and polar areas, 

 and compensatory polar currents flow towards the 

 equator, absorbing heat from the waters of temperate 

 and equatorial areas. Winds act in an analogous way. 

 Water is evaporated where the solar radiation is intense, 

 and heat is absorbed in the transformation of water 

 into aqueous vapour. Then this water vapour is 

 transported in the winds into regions where it becomes 

 condensed and precipitated as rain or snow, heat being 

 emitted in this condensation. In all these movements 

 there is friction, and this friction transforms to heat. 

 In all the effect is the general distribution over the earth 

 of the heat which the equatorial regions receive in 

 excess of that which the polar regions receive. Other 

 mechanical effects are also produced by oceanic and 

 atmospheric circulations — the denudation of the coasts 

 by tides and storms, the erosion of the land by rivers, 

 rains, snow, and ice, the transport of dust in winds, etc. 



