Problems of Astronomy 



omy. If I apply this title it is because that 

 branch of the science to which the spectroscope 

 has given birth is often called the new astronomy. 

 It is commonly to be expected that a new and 

 vigorous form of scientific research will supersede 

 that which is hoary with antiquity. But I am 

 not willing to admit that such is the case with the 

 old astronomy, if old we may call it. It is more 

 pregnant with future discoveries to-day than it 

 ever has been, and it is more disposed to welcome 

 the spectroscope as a useful handmaid, which 

 may help it on to new fields, than it is to give 

 way to it. How useful it may thus become has 

 been shown by a Dutch astronomer, who finds 

 that the stars having one type of spectrum belong 

 mostly to the Milky Way, and are farther from 

 us than the others. 



In the field of the newer astronomy perhaps 

 the most interesting work is that associated with 

 comets. It must be confessed, however, that 

 the spectroscope has rather increased than 

 diminished the mystery which, in some respects, 

 surrounds the constitution of these bodies. 

 The older astronomy has satisfactorily accounted 

 for their appearance, and we might also say for 

 their origin and their end, so far as questions of 

 origin can come into the domain of science. It 

 is now known that comets are not wanderers 

 through the celestial spaces from star to star, 

 but must always have belonged t to our system. 

 But their orbits are so very elongated that thou- 

 sands, or even hundreds of thousands of years 

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