226 ANNUAL OF SCIENTIFIC DISCOVERT. 



diminish in circumference, but was forced to pucker into ridges, 

 just as we see in the case of an api>le diyinjj^ u]). The iij)plo 

 assumes a wizonod appearance ; so did the earth. The wrinkles 

 arc mountain chains. 



Tiic spectroscopic confirmation of those ideas, thou2:h indirect, 

 follows necessarily from the su])port which that instrument lends 

 to the nebular hypothesis. If the earth was once an ignited gas, 

 it is certain tiiat it also presented subsequently a molten form. 

 And its geometrical shape, that of an oblate spheroid, the figure 

 naturally assume»l by a x-otating liquid mass, is an important link 

 in the chain of evidence. 



Another rdlcction naturally suggests itself to any one thinking 

 about these matters. We know tiiat heat was the force con- 

 cerned in keeping the materials of our solar system in the gase- 

 ous state, for by its aitl we can again bring most of them into that 

 form. The escape of heat was the cause of the solidification of 

 the present crust of the earth. Where has all that immense 

 amount of heat gone to ? 



It escai)ed altogether as radiant heat, moving in straight lines. 

 Is it lost in the abysses of the universe, or is it somewhere col- 

 lected together to melt worn-out worlds into nebulae again, and 

 cause them to run again the course they have before pursued •>* 

 Can we discover the scheme by whicrh perishing systems are re- 

 placed by new ones, and the grand East Indian idea, of a multi- 

 Slicity of worlds in an infinity of time, realized? How, when the 

 ght of our sun has faded out, shall our solar system be revivi- 

 fied, and re-supplicd with the force it has lost? These are ques- 

 tions that remain to be solved. We are satisfied that matter and 

 force are eternal ; but what their laws of distribution and opera- 

 tion in space and time are, the intellect of man has yet to 

 discover. 



And if there has been a gradual formation of planets within our 

 solar system, beginning at its confines, one after another losing 

 its internal heat and becoming dependent on the sun for warmth, 

 does not another thought occur to us ? Has not life followed the 

 inward march of heat? Is it not possible that there was a time 

 when plants and animals, such as we have here, were able to 

 exist on the exterior planets, favored by their genial heat? The 

 last traces may not have disappeared from them. And may not 

 the types of low forms of organized things, that inhabited this 

 earth in early geological times, have passed inward toward the 

 sun, where surrounding physical conditions favored them in a 

 manner that has ceased here ? Are there on Venus the radiata, 

 mollusea, etc., belonging to our planet ages ago? Do tjpes of 

 life exist in the more distant planets, of some grade higher than 

 our own? We see on the earth the migrating animals, that 

 cannot stand the vicissitudes of summer and winter, follow the 

 sun southward in winter, and driven before him northward in the 

 summer. Is there in the solar system a similar obedience to heat 

 and its effects, and an ever inward flowing tide of life ? — Galaxy. 



