1912-1913-] Some A stronomical Problems. 4 1 



but it certainly has demonstrated the presence of large 

 quantities of helium, a derivative of radium, having an atomic 

 weight of 4. Eadium holds the field in the scientific arena, 

 and is the most doughty champion that has appeared there 

 for a long time. Old and apparently well-established theories, 

 and even generalisations, have either gone down before him 

 or suffered considerable metamorphism. It is easy to see the 

 cosmic importance of a discovery of this kind. If radium 

 affords the key to the problem of our sun, then why not give 

 it also a free hand among the fixed stars, all distant suns, 

 and then radium will soon have the universe on his shoulders, 

 making Atlas of old a pigmy of utter insignificance ? 



Taking all things into consideration, we may allow that the 

 radium theory gives us a provisional solution of the solar 

 problem, but all the same the unexpected may happen once 

 more, and some new and profound secret of nature be revealed 

 which yet again may entirely alter our interpretation of the 

 facts. 



It is curious to observe, before leaving this subject, that 

 while the earth is entirely dependent on the sun for every form 

 of energy displayed here, yet we, the inhabitants of the earth, 

 can only apply a comparatively very small part of the daily 

 supply of that energy to the uses and wants of our now vast 

 and complicated civilisation, apart of course from the annual 

 gift of the fruits of the earth. Our age is an age of energy, 

 derived from the mineral coal, and human society is almost 

 entirely dependent upon it. Now the vast stores of energy 

 locked up in coal were derived from the sun many millions of 

 years ago, and the whole of it came to us, through the fathom- 

 less void of space which separates us from the sun, travelling 

 along those mysterious intangible rays of light. We are in 

 very deed living on the past, and spending a vast inheritance 

 of wealth out of capital, the supply of which, it is needless to 

 remark, is not limitless. We may draw our own conclusion, 

 but it seems as if a time of anxiety will come at last, and 

 science must cast about for some new source of energy. 

 Perhaps before the coal is all gone, or become too dear, men 

 may have found a way to harness the energy locked up in the 

 elementary atoms. 



The planets that revolve about the sun in company with 



