664 THE POPULAR SCIENCE MONTHLY. 



during which it can have maintained the earth in a habitable 

 condition is proportionally shortened, for we can not suppose that 

 animal and vegetable life could be developed under the dominion 

 of a distinctively variable star. The assumption is here made, of 

 course, that a variable star is really a sun and not a cloud of 

 meteorites in collision, or a partially condensed nebula, and that 

 its planets, if it is ever to have any, have already been formed. 

 Progress in the other direction that is, from the white star toward 

 the red star and variable star stage would seem to supply longer 

 periods of unvarying solar radiation for the evolution of planetary 

 life, since a sun developing in that way would become a stable 

 radiator sooner than if it had first to free itself from a sheathing 

 of absorbing vapors created, it may be, by its own action at a cer- 

 tain stage of its career rather than left behind as a subsiding rem- 

 nant of the original nebula. 



"We have remarked that, so far as the records of human history 

 inform us, the emission of light and heat by the sun has never 

 seriously varied. Yet it has been thought, though the evidence 

 is not clear, that there are geological indications of considerable 

 variations in the amount of solar radiation in past time, and the 

 famous myth of Phaeton driving the chariot of the sun and getting 

 so far out of his road that he endangered the earth and made it 

 smoke with unwonted heat, has often been referred to as a pos- 

 sible tradition of some extraordinary outburst of solar heat with- 

 in the period of man's existence. The variable character of sun- 

 spot phenomena certainly does not contradict that supposition. 

 The margin of existence is so narrow for many forms of life that 

 no very great change would be required to cause a disaster. Still, 

 notwithstanding the vagaries of sun-spots, and the apparent anal- 

 ogy between the sun and the variable stars, it would not do to 

 assume that the earth is at present in any danger from a changing 

 mood in its great governor and benefactor. So far as positive 

 records serve as an indication of the future, there is every reason 

 to believe that the sun will long continue in its present condition, 

 and that astronomers a million years hence, if some cataclysm 

 arising from ulterior causes does not intervene, may still be found 

 studying the sun, having probably by that time ascertained 

 whether it is getting hotter or colder. But it would not be safe 

 to assume that any astronomers will be left' upon the earth five 

 million years hence. 



Tnia inquiries of the British Labor Commission have brought out the fact that 

 some of the workmen believe that the state should by penal enactment prevent all 

 men over sixty years old from working for wages, giving them instead of work a 

 pension. Their theory is that to give work for pay is a benefaction to the com- 

 munity, for which gratitude and a reward are due them. 



