SIDEREAL ASTRONOMY. 331 



amidst these high objects, to submit himself to the common 

 coil of worldly affairs. An eminent name is present to our 

 memory when we make this remark. While lamenting, as 

 all must do, the recent loss of Arago, we may express our 

 belief that he himself found deep cause to regret that change, 

 which removed him for a time from the scientific labours of 

 the Observatory and Institute to the revolutionary govern- 

 ment of his country. This avowal indeed we have ourselves 

 more than once heard him to make. 



The ensuing chapter ' on the Number, Distribution, and 

 Colour of the Stars, and on the Milky Way,' has additional 

 value in some numerical results of great exactness, furnished 

 to Humboldt by that eminent astronomer Argelander of 

 Bonn. From various combinations of the data afforded by 

 star-catalogues, he obtains as a mean number from 5,000 to 

 5,800 stars visible to the naked eye throughout the entire 

 heavens ; while, carrying the list forwards to telescopic stars 

 of the ninth magnitude, he finds a total result in round 

 numbers of 200,000 stars ! And here again we come upon 

 one of those curious relations so frequent in astronomy, 

 which transcend all common calculation. The imagination, 

 unaided by science, might well conceive that this host of 

 numbers would crowd and cover every point in the sky ; and 

 would hardly lend belief to the assertion that each of these 

 200,000 stars, if equally distributed, would occupy to itself 

 an area almost equal to that of the full moon. Yet so it is ; 

 the fact being very precisely determined that 195,290 sur- 

 faces of the moon, in its mean diameter, would be required 

 to cover the whole heavens. This relation is of course a 

 mere accident; the stars being very unequally distributed, 

 and their classification by apparent magnitudes an artificial 

 one. But there is value in the illustration it affords ; and 

 legitimate pleasure as well as instruction in the results which 

 these ponderous numbers thus place before us. 



