Prospecting the Skies 



More discoveries in astronomy are 

 now made in a single night than all the 

 earlier astronomers made collectively 



By Dr. C. Furness 



Professor of Astronomy in Vassar College 



WITH only our eyes to help us, we 

 would know no more about the 

 stars than did the ancient Greeks. 

 What we need is an artificial eye — some- 

 thing to be placed in front of our own, 

 something which, by gathering the light 

 reflected from distant bodies, brings those 

 bodies miraculously nearer to us. Because 

 Galileo was the first to employ such arti- 

 ficial aid in astronomy, he still lives in the 

 popular mind as the greatest of all astron- 

 omers. It is indeed wonderful what 

 Galileo actually succeeded in discovering 

 with his artificial eye — a telescope which 

 had lenses no bigger than those of a pair 

 of spectacles. But the discoveries — using 

 the word in its broadest sense — made by 

 the modern astronomer are in every way 

 as startling, in every way as important as 

 those it was the privilege of the great 

 Italian to record. If the modern astron- 

 omer's explorations are not so well-known, 

 it is because they are so extraordinarily 

 numerous, and because they have lost in 

 consequence something in dramatic novelty. 

 Only a revelation of unprecedented im- 



Comet-seeking tele- 

 scope attached to 

 observation chair 



portance re- 

 ceives attention 

 in the news- 

 papers. 



Astronomers 



Have Become 



Specialists 



The artificial 

 eyes that we call 

 telescopes have 

 gained wonder- 

 fully in power since Galileo's day. They 

 are used more systematically, too. As- 

 tronomers have become specialists. Some 

 of them confine their studies to comets; 

 others, to the planets; still others to the 

 sun. And there are many who hardly ever 

 look through a telescope at all, but who 

 simply measure the positions of stars on 

 photographic plates. 



To show just how one of these specialists 

 goes to work, let me ask you to consider 

 the procedure of the comet-seeker. Comets 

 usually reach their greatest brightness 

 when thev are nearest the sun, at which 



Change in the nebulosity about Nova Persei, the brilliant new star discovered in 1901. Long 

 exposure photographs showed the star to be enveloped by an extensive nebula. A second exposure 

 talcen weeks later showed that the nebula had expanded outward. Comparison of the portion in 

 the white squares with reference to the three largest stars gives an idea of this expansion 



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