TJie Earth in the Comet's Tail. 65 



George Williams, Esq., of Liverpool, which entirely altered my 

 view of its nature. From his statement it appears that about 

 12h. 30m. he had seen the same ray in the direction of Ursa 

 Major, as well as another, somewhat brighter, which diverged 

 towards Cassiopea, the brightest part of the latter being at 

 some distance from the comet, and appearing to recede from it 

 until it was altogether lost. Like myself he had thought at the 

 time that both might be cirrus clouds only ; but that each should 

 point to the nucleus of the comet, he considered a circumstance 

 worthy at least of a remark, and he, therefore, recorded the 

 appearance in a beautiful sketch, which I have his obliging 

 permission to make use of, and of which a copy is here given. 

 It was not surprising that I had missed the eastern ray, as that 

 part of the sky was partially obscured by trees from my station 

 at the telescope, and was wholly invisible afterwards from the 

 window ; but we had previously noticed that the right side of 

 the tail had appeared to the naked eye to strike out from the 

 coma for a few degrees in a more easterly direction; this, 

 though not traceable as a separate stream, was, I have little 

 doubt, the point of departure of the ray in Cassiopea. Thus 

 it seems established, by the concurrence of two observers at 

 distant stations, that these rays were not clouds, but the per- 

 spective representation of the sides of a conical or cylindrical 

 tail, hanging closely above our heads, and probably just being 

 lifted up out of our atmosphere. The rapid movement which I 

 had noticed in the western beam, and which, according to Mr. 

 Williams' sketch, was still continued afterwards, will, on 

 careful consideration, be found in full accordance with this idea : 

 for the tail was then receding so speedily from the earth that 

 the sides of the outspread fan must, from the effect of per- 

 spective, have closed up with great swiftness towards the centre, 

 and thus would be produced that apparent rising in the sky by 

 which I was misled : the great amount, too, of that closing up 

 in proportion to the time of the observation, shows how very 

 near the object must even at that moment have been to us ; 

 and yet the central streams must obviously have been consider- 

 ably closer to us than the apparent sides of the cone or 

 cylinder. So that, from a review of the whole phenomenon, it 

 seems not only certain that we were then in the immediate 

 vicinity of the tail, but much more probable that we had actually 

 passed through it, as Mr. Hind supposed, than that there still 

 remained, according to the German astronomer, M. Pape, an 

 interval of two millions of miles. 



The next night proved cloudy, and I never saw ths western 

 ray afterwards, but it may have been the same with that noticed 

 by some observers on July 10 as deviating towards the star 

 [a Bootis. 



vol. i. — no. I. F 



