CHAPTER XI. 



ASTRONOMY AND COSMIC THEORIES. 



The wilder'd mind is tost and lost, 



O sea, in thy eternal tide ; 

 The reeling brain essays in vain, 



O stars, to grasp the vastness wide ! 

 The terrible, tremendous scheme 



That glimmers in each glancing light, 

 O night, O stars, too rudely jars 



The finite with the infinite ! 



J. H. Dell. 



MANY of the most striking discoveries in this science 

 have been already described under Spectrum Analysis; 

 but there remain a few great advances, due either to ob- 

 servation or to theory, which are of sufficient popular 

 interest to demand notice in any sketch, however brief, 

 of the scientific progress of the century. 



With the single exception of Uranus, discovered by 

 Herschel in 1781, no addition had been made to the five 

 planets known to the ancients till the commencement of 

 the present century, when Ceres, the first of the minor 

 planets, was discovered in 1801, and three others be- 

 tween that date and 1807. No more were found till one 

 was added in 1845, and another in 1847. Since that 

 time no year has passed without the detection of one or 

 more new planets belonging to the same system, till in 

 September, 1896, their number amounted to 417. 

 These small bodies form a kind of planetary ring situ- 

 ated between Mars and Jupiter, where it had long been 



