2 COSMOS. 



which the present condition of our knowledge is more parti- 

 cularly based. These volumes of my work, must, therefore, 

 in accordance with a remark already made (Cosmos, vol. iii, 

 pp. 2 6), be considered merely as an expansion and more 

 careful exposition of the General Picture of Nature (Cosmos, 

 vol. i, pp. 62 369), and as the uranological or sidereal sphere 

 of the Cosmos was exclusively treated of in the two last 

 <jolumes, the present volume will be devoted to the con- 

 ideration of the telluric sphere. In this manner the ancient, 

 simple, and natural separation of celestial and terrestrial 

 objects has been preserved, which we find by the earliest 

 evidences of human knowledge to have prevailed among all 

 nations. 



As in the realms of space, a transition to our own plane- 

 tary system from the region of the fixed stars, illumined by 

 innumerable suns, whether they be isolated or circling round 

 one another, or whether they be mere masses of remote 

 nebulae, is indeed to descend from the great and the universal 

 to the relatively small and special ; so does the field of our con- 

 templation become infinitely more contracted when we pass 

 from the collective solar system, which is so rich in varied 

 forms, to our own terrestrial spheroid, circling round the 

 sun. The distance of even the nearest fixed star, a Centauri, 

 is 263 times greater than the diameter of our solar system, 

 reckoned to the aphelion distance of the comet of 1680; and 

 yet this aphelion is 853 times further from the sun than our 

 earth (Cosmos, vol. iv, p. 546). These numbers, reckoning 

 the parallax of a Centauri at O."9187, determine approximately 

 both the distance of a near region of the starry heavens 

 from the supposed extreme solar system and the distance 

 of those limits from the earth's place. 



Uraiiology, which embraces the consideration of all that 

 fills the remote realms of space, still maintains the character 

 it anciently bore, of impressing the imagination most deeply 

 and powerfully by the incomprehensibility of the relations 

 of space and numbers which it embraces ; by the known 

 order and regularity of the motions of the heavenly bodies ; 

 and by the admiration which is naturally yielded to the 

 results of observation and intellectual investigation. This 

 consciousness of regularity and periodicity was so early im- 

 pressed upon the human mind that it was often reflected in 



