THE WORLD BEYOND OUR SENSES 



dence thus far offered, however, has not seemed 

 convincing. Scientific men, therefore, find them- 

 selves in the curious position of believing that such 

 an evolution of the elements has taken place, and 

 no doubt is still going on in distant suns, while 

 they doubt the sufficiency of the evidence*that has 

 thus far been put forward as a demonstration. 



The spectroscope has afforded a yet further dip 

 into the world beyond our senses. That is, in the 

 detection of dark suns, invisible through even the 

 finest telescopes. A very early discovery in the 

 history of the instrument was that if the source of 

 light in spectral analysis is moving towards or re- 

 ceding from the prism, the characteristic lines of 

 the spectrum shift slightly, up or down. By means 

 of this curious circumstance, it has been possible to 

 calculate the speed of some of the stars, and to 

 know whether they are running away from or ap- 

 proaching our solar system. Even their orbits 

 have been mapped, and this, too, has led to the 

 recognition of many new double-stars, suns which 

 are revolving about one another, and appear some- 

 times as one, sometimes as two. In some cases, 

 the twin-star never appears, but the form of the 

 orbit is so clearly defined as to make it certain that 

 a twin exists. 



In brief, it has been possible to detect, locate, 



