X THE STARRY HEAVENS 429 



all of course preceded, and preceded again 

 by another incalculable period, the very com- 

 mencement of that geological history which 

 itself indicates a lapse of time greater than 

 human imagination can realise. 



Thus, then, however far we penetrate in 

 time or in space, we find ourselves surrounded 

 by mystery. Just as in time we can form no 

 idea of a commencement, no anticipation of 

 an end, so space also extends around us, 

 boundless in all directions. Our little Earth 

 revolves round the mighty Sun ; the Sun 

 itself and the w^hole solar system are moving 

 with inconceivable velocity towards a point 

 in the constellation of Hercules ; together 

 with all the nearer stars it forms a cluster 

 in the heavens, which appears to our eyes as 

 the Milky Way ; while outside our star cluster 

 again are innumerable others, which far trans- 

 cend, alike in magnitude, in grandeur, and 

 in distance, the feeble powers of our finite 

 imagination. 



