PROGRESS OF MODERN ASTRONOMY 



skies, and his discoveries followed one another in be- 

 wildering profusion. He found various hitherto un- 

 seen moons of our sister planets; he made special 

 studies of Saturn, and proved that this planet, with its 

 rings, revolves on its axis ; he scanned the spots on the 

 sun, and suggested that they influence the weather of 

 our earth ; in short, he extended the entire field of solar 

 astronomy. But very soon this field became too small 

 for him, and his most important researches carried 

 him out into the regions of space compared with which 

 the span of our solar system is a mere point. With his 

 perfected telescopes he entered abysmal vistas which 

 no human eye ever penetrated before, which no human 

 mind had hitherto more than vaguely imagined. He 

 tells us that his forty-foot reflector will bring him light 

 from a distance of "at least eleven and three-fourths 

 millions of millions of millions of miles" light which 

 left its source two million years ago. The smallest 

 stars visible to the unaided eye are those of the sixth 

 magnitude; this telescope, he thinks, has power to 

 reveal stars of the i342d magnitude. 



But what did Herschel learn regarding these awful 

 depths of space and the stars that people them ? That 

 was what the world wished to know. Copernicus, 

 leo, Kepler, had given us a solar system, but the 

 ; had been a mystery. What says the great re- 

 <>r are the stars points of light, as the ancients 

 taught, and as more than one philosopher of the eigh- 

 teenth century has still contended, or are they suns, as 

 s hold? Herschel answers, they are suns, each 

 and every one of all the millions suns, many of them, 

 larger than the one that is the centre of our tiny system. 



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