84 THE PROBLEMS OF ASTRONOMY. 



appropriately claim the admiration of mankind through all time than 

 that of Copernicus. Scarcely any great work was ever so exclusively 

 the work of one man as was the heliocentric system the work of the 

 retiring sage of Frauenburg. No more striking contrast between the 

 views of scientific research entertained in his time and in ours can be 

 seen than that seen in the fact that, instead of claiming credit for his 

 great work, he deemed it rather necessary to apologize for it and, so 

 far as possible, to attribute his ideas to the ancients. 



A century and a half after Copernicus followed the second great 

 step, that taken by Newton. This was nothing less than showing that 

 the seemingly complicated and inexplicable motions of the heavenly 

 bodies were only special cases of the same kind of motion, governed 

 by the same forces, that we see around us whenever a stone is thrown 

 by the hand or an apple falls to the ground. The actual motions of 

 the heavens and the laws which govern them being known, man had 

 the key with which he might commence to unlock the mysteries of the 

 universe. 



When Huyghens, in 1656, published his Systema Saturnium, where 

 he first set forth the mystery of the rings of Saturn, which, for nearly 

 half a century, had perplexed telescopic observers, he prefaced it with 

 a remark that many, even among the learned, might condemn his 

 course in devoting so much time and attention to matters far outside 

 the earth, when be might better be studying subjects of more concern 

 to humanity. Notwithstanding that the inventor of the pendulum 

 clock was, perhaps, the last astronomer against whom a neglect of 

 things terrestrial could be charged, he thought it necessary to enter 

 into an elaborate defense of his course in studying the heavens. Now, 

 however, the more distant objects are in space — I might almost add 

 the more distant events are in time — the more they excite the attention 

 of the astronomer, if only he can hope to acquire positive knowledge 

 about them. Not, however, because he is more interested in things 

 distant than in things near, but because thus he may more completely 

 embrace in the scope of his work the beginning and the end, the 

 boundaries of all things, and thus, indirectly, more fully comprehend 

 all that they include. From his standpoint 



"All are but parts of one stupendous whole, 

 Whose body nature is and God the soul." 



Others study nature and her plans as we see them developed on the 

 surface of this little planet which we inhabit; the astronomer would 

 fain learn the plan on which the whole universe is constructed. The 

 magnificent conception of Copernicus is, for him, only an introduction 

 to the yet more magnificent conception of infinite space containing a 

 collection of bodies which we call the visible universe. How far does 

 this universe extend? What are the distances and arrangements of 

 the stars? Does the universe constitute a system 1 ? If so, can we com- 

 prehend the plan on which this system is formed, of its beginning and 



