v BELIEF AND EVIDENCE 103 



who has considered the facts that the apparent move- 

 ments of the stars are entirely due to the daily spin of 

 the earth, and the annual journey round the sun, is able 

 to believe that the weather can be determined by the 

 aspects of the stellar heavens at any time of day or year. 

 Certain groups of stars are visible at particular seasons, 

 but they have nothing whatever to do with the cause 

 of the seasons, which would, indeed, be of precisely the 

 same character as they are now, even if every star in 

 the sky ceased to shine. The stars are, in fact, much 

 too far removed from the solar system to take any part 

 in causing weather changes. 



The nearest of all the stars is a quarter of a million 

 times farther away from us than is the sun ; and the 

 heat we receive from a star is so small in amount 

 that it can only be detected with instruments of 

 extreme delicacy. Whatever the temperatures of the 

 stars may be, the stellar heat that reaches the earth 

 is almost inappreciable. The best measurements avail- 

 able, made by Prof. E. L. Nichols at the Yerkes Obser- 

 vatory, California, with an instrument capable of 

 detecting a difference of temperature of less than the 

 ten-millionth part of a degree on a Centigrade ther- 

 mometer, shows that a square foot of the earth's surface 

 receives from the bright reddish star Arcturus only as 

 much heat as would be received from a standard candle 

 nearly six miles away, even if none of the heat of the 

 candle were absorbed during the passage of the rays 

 through the air. To produce the same heating effect 

 as the brilliant bluish- white star Vega, a standard candle 

 would have to be taken to a distance of nearly nine miles. 



Dr. S. Chapman estimates that the total starlight is 

 only about equal to that of a one candle-power lamp 

 at a distance of nearly twelve yards, or of a sixteen 



