AND ITS INHABITANTS 7 



of the telescope, the evidence of their composite nature being 

 revealed only through the analysis of their light by the spectro- 

 scope. These double stars revolve swiftly about each other, 

 but such internal motions must be sharply distinguished in 

 thought from the streaming or drifting of the stars as parts of 

 the great stellar system. Relatively to the sun they are found 

 to move through space with speeds averaging between 10 and 

 30 miles per second, but ranging from less than 10 to more 

 than 200 miles rjer^ecpnd. They do not move, however, 

 singly and in closed orBits, but rather in broadly scattered 

 groups whose paths are almost straight lines. These courses 

 of the stars must slowly curve under the aggregate attraction 

 of the millions of stars, but can never return into themselves. 

 The paths of groups of stars intersect other groups and are 

 to some extent interwoven among themselves. These groups 

 have been found to be integrated into two greater groups inter- 

 meshed among each other and forming two great star streams 

 whose average motions are in opposite directions. With the 

 passage of millions of years, the stars thus continually enter 

 into new relations and build new configurations in the skies: 

 a myriad host of stellar fireflies, the living and the dead, 

 streaming through space hundreds of millions of miles per 

 year. 



Although the stars are so great in number, their distances 

 from each other average tens of millions of millions of miles, 

 those in our part of the stellar system averaging between sixty 

 and eighty trillion^. The star nearest to the sun, a Centauri, 

 happens, however, to be at a lesser distance of about twenty- 

 six trillions of miles. 



To bring down the dimensions of the universe to finite 

 comprehension, we must divide the scale of nature by a 

 thousand million. Then the earth would be represented by a 

 pebble half an inch in diameter, circling once a year about a 

 sun 4.5 feet in diameter, at a distance of 500 feet. The nearest 



