60 FROM NEBULA TO NEBULA 



tinually force their way to the surface and to freedom 

 (forming what astronomers technically call "convec- 

 tion currents") there to radiate away their cargoes of 

 heat, to condense, and to resume their original place as 

 part and parcel of the stupendous solar gravistatic 

 press prepared to go through the same cycle of per- 

 formance again. And so on until the sun himself shall 

 cease to be. 



Hence it is true that the sun is continually "falling 

 in upon himself," but not as Helmholtz conceived it to 

 do. For Helmholtz failed to divine the real secret, 

 namely, that the sun is at once pestle, mortar and grist, 

 and that his central parts instead of packing tighter are 

 retranslated into their elementary gases and so regain 

 their own former "energy of position." But the sun is 

 not contracting. 



Briefly, then, the solar heat is due to the continuous 

 conversion of the sun?s substances into gases by virtue 

 of the pressure of the superincumbent layers falling to- 

 ward Ms center, the space allowing for such fall being 

 vacated by the said gases, which rise to the surface upon 

 the wings of their own explosive force, there render up 

 their heat, condense, and regain their original energy of 

 position as part of the great solar press. 



Should I stop here I had told but half the truth, 

 for I maintain that even were the body composed only 

 of solid refractory materials that had reached a con- 

 dition of stable compactness * ^K ; production of heat 

 would not be in the least curtailed. And this is really 

 what I have primarily in mind when I use the expression 

 GBAVISTATIC HEAT. For pressure even without visible 

 movement is yet generating heat, for the simple reason 

 that heat is a state of matter due to the activity of its 



