138 



III. 



NUMBER, DISTRIBUTION, AND COLOUR OF THE FIXED 



STARS. STELLAR MASSES (STELLAR SWARMS). THK 



MILKY WAY INTERSPERSED WITH A FEW NEBULOUS 

 SPOTS. 



WE have already, in the first section of this fragmentary As- 

 trognosy, drawn attention to a question first mooted by Olbers. 1 

 If the entire vault of heaven were covered with innumerable 

 strata of stars, one behind the other, as with a wide-spread 

 starry canopy, and light were undirninished in its passage 

 through space, the sun would be distinguishable only by 

 its spots, the moon would appear as a dark disc, and amid 

 the general blaze not a single constellation would be 

 visible. During my sojourn in the Peruvian plains, between 

 the shores of the Pacific and the chain of the Andes, I was 

 vividly reminded of a state of the heavens, which, though 

 diametrically opposite in its cause to the one above referred 

 to, constitutes an equally formidable obstacle to human 

 knowledge. A thick mist obscures the firmament in this region 

 for a period of many months, during the season, called el 

 tiempo de la garua. Not a planet, not the most brilliant stars 

 of the southern hemisphere, neither Canopus, the southern 

 Cross, nor the feet of the Centaur, are visible. It is frequently 

 almost impossible to distinguish the position of the moon. 

 If by chance the outline of the sun's disc be visible during 

 the day it appears devoid of rays, as if seen through 

 coloured glasses, being generally of a yellowish red, some- 



1 Vide supra, p. 46 and note. 



