i54 COSMOS. 



hour a ray of light traverses over a space of 592 milhons ol 

 miles. While, according to the theogony of Hesiod, the di- 

 mensions of the universe were supposed to be expressed by the 

 time occupied by bodies in falling to the ground (" the brazen 

 anvil was not more than nine days and nine nights in falling 

 from heaven to earth"), the elder Herschel was of opinion* 

 that light required almost two millions of years to pass to the 

 Earth from the remotest luminous vapor reached by his forty- 

 foot reflector. Much, therefore, has vanished long before it 

 is rendered visible to us — much that we see was once differ- 

 ently arranged from what it now appears. The aspect of the 

 starry heavens presents us with the spectacle of that which 

 is only apparently simultaneous, and however much we may 

 endeavor, by the aid of optical instruments, to bring the mild- 

 ly-radiant vapor of nebulous masses or the faintly-glimmering 

 starry clusters nearer, and diminish the thousands of years 

 interposed between us and them, that serve as a criterion of 

 their distance, it still remains more than probable, from the 

 knowledge we possess of the velocity of the transmission of 

 luminous rays, that the light of remote heavenly bodies pre- 

 sents us with the most ancient perceptible evidence of the ex- 

 istence of matter. It is thus that the reflective mind of man 

 is led from simple premises to rise to those exalted heights of 

 nature, where, in the hght-illumined realms of space, " myriads 

 of worlds are bursting into life like the grass of the night. "f 

 From the regions of celestial forms, the domain of Uranus, 

 we will now descend to the more contracted sphere of terres- 

 trial forces — to the interior of the Earth itself A mysterious 

 chain links together both classes of phenomena. According 

 to the ancient signification of the Titanic myth,$ the powers 

 of organic life, that is to say, the great order of nature, depend 

 upon the icombined action of heaven and earth. If we sup- 

 pose that the Earth, like all the other planets, primordially 

 belonged, according to its origin, to the central body, the Sun, 

 and to the solar atmosphere that has been separated into neb- 



* " Hence it follows that the rays of light of the remotest nebulae 

 must have been almost two millions of years on their way, and that 

 consequently, so many years ago, this object must already have had 

 an existence in the sidereal heaven, in order to send out those rays by 

 which we now pjrceive it." William Herschel, in the Phil. Trans. 

 for 1802, p. 498. John Herschel, Astron., § 590. Arago, in the Jn- 

 nuaire, 1842. p. 334, 359, and 382-385. 



t From ray brother's beautiful sonnet '' Freiheitund Gesetz." (Wil> 

 ttclm von Humboldt, Gesammelte Werke, bd. iv., s. 358, No. 25.) 



I Otfried Muller, Prolegomena, s. 373. 



