H. A. Newton — The Story of Bielals Comet. 85 



lision of the earth and the comet. The comet was first seen by 

 Sir John Herschel in September. In his 20-foot reflecting tel- 

 escope he saw it pass centrally over a group of small stars of 

 the 16th or 17th magnitude. The slightest bit of fog would 

 have at once blotted out the stars. Through the comet, how- 

 ever, they looked like a nebula, resolvable, or partly resolvable, 

 into stars. How thick the cometic matter was we do not know. 

 Its extent, laterally, was not less than 50,000 miles. Again M. 

 Struve saw it pass centrally over a star of the ninth magni- 

 tude. A like star was seen in the telescope at the same time, 

 so that he was able to say that the comet did not dim in the 

 least the one which it covered. The comet, as the figure (fig. 4) 

 shows, was in 1832 always at a great distance from the earth. 



Another six and two-thirds years brings us to 1839. The 

 comet came to perihelion, at P, in July. The earth and comet 

 were on opposite sides of the sun both before and after July, 

 and of course the comet was not seen. 



Position in 1845. — Another circuit was finished in 1845-6. 

 The comet was visible then during five months, from a to b 

 (fig. 5), or as viewed from the sun through nearly half its cir- 

 cuit. At this time it was that the comet became all at once 

 famous. 



On the 29th of December Mr. Herrick (then Librarian of Yale 

 College) and Mr. Francis Bradley (then in the City Bank) were 

 watching the comet through the Clark telescope in the Athe- 

 neum tower yonder. They saw a small companion comet 

 beside the larger one! What did it mean? Had the comet a 

 satellite like the earth's moon? Or had the comet been split 

 by some convulsion ? Two weeks later the companion comet 

 was seen by Lieut. Maury and Professor Hubbard at Wash- 

 ington, and two days after that, it was seen by two or three 

 European astronomers. 



Changes were seen in the larger telescopes that increased the 

 mystery. The faint companion grew in size and brilliancy. 

 Each comet threw out a tail. Then the smaller one had two 

 tails. Then the larger one had a pointed, or diamond-shaped, 

 rather than a round head. Two nuclei were seen in the larger 

 one, and it also had two tails. An arch of light was thrown 

 over from one to the other. For some days in February the 

 companion was the brighter of the two. Presently three tails 

 were seen running from the primary, and three cometary frag- 

 ments (one observer says five) around its nucleus. What 

 could it all mean ? Do you wonder that astronomers were ex- 

 cited by these wizard changes? 



The companion comet was seen in Washington by Maury 

 and Hubbard two weeks after it was seen here by Herrick and 

 Bradley. Professor Joseph Hubbard was the son of a resident 



