14 THE CKEED OF SCIENCE, RELIGIOUS AND MORAL. 



mainland of the sun's nebular continent, and all the 

 more when we reflect that the former existence of 

 the islands themselves is not beyond the reach of doubt. 



To conclude : we know nothing for certain respecting 

 the mode of origination of the earth, the sun, the planets, 

 the stars. We believe, on the showing of Science, that 

 the sun could not have existed from eternity, because his 

 heat is a limited quantity that Jcould not have lasted 

 perpetually unless recruited from sources of which 

 Science has no knowledge. But still, there may now be, 

 and there may have been, such sources.* Nor could we 

 be certain to the contrary, unless we were assured that 

 we know all the physical forces in nature, and that none 

 of these, either separately or by their conjoint action, 

 could have kept up an eternal supply of solar heat. 

 Assuming, however, as more probable, that the sun has 

 not existed from eternity, we are sure that he gathered 

 his tires by natural causes. But we are not sure that 

 the only cause was the impact of falling masses of matter, 

 or the condensation of his diffused matter into closer 

 compass, as Helmholtz has it. And assuming that the 

 sun had a beginning in time, we are equally sure that 

 the earth had also a beginning, since it could not well 

 have existed in the sun's absence. But we are not sure 

 that the earth (any more than the sun) was formed at 

 white heat by the rushing together of its materials, much 

 less that it is the solidified result of a prodigious ring of 

 vapour, thrown off ages ago from a revolving vaporous 

 sphere in the course of its contracting and cooling down 

 to the sun. 



Both these hypotheses should, indeed, be treated with 

 the respect that is due to the guesses of men of genius. 



* Since the above was written, Dr. Siemens, in his Ccnservation of 

 Solar Energy, has advanced a positive theory of such possible sources. 



