CHAPTER VI. 



Advance of Astronomy. 



from copernicus to newton. 



Astronomy an Ancient Science. — Astronomy is 

 usually ranked as the most ancient of the concrete 

 sciences, and this at least is certain that evidence of 

 astronomical observation is furnished by the posi- 

 tion of buildings which are much older than all 

 written records. Perhaps one of the first scientific 

 discoveries to become clear and definite was the dis- 

 covery of the year, with its fine demonstration-lesson 

 of recurrent sequences. From that unknown date to 

 the latest announcements from the observatories of 

 Greenwich and Potsdam, Harvard and Lick, there 

 extends a long procession of discoveries, sometimes 

 almost monotonous in their continuity and sameness, 

 but relieved at intervals by some great and novel 

 achievement which has given a new meaning to the 

 whole. 



That astronomy reached a stable position sooner 

 than the other sciences was partly because the sub- 

 lime subject attracted men of genius who " attended 

 their minds thereunto," and partly because a great 

 part of astronomy is concerned with simple relations 

 of distance, mass, and motion. 



Three Main Chapters. — Balfour Stewart has 

 summed up the long history of astronomy in three 



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