3 1 Observations of the Appearance of the Comet. 



tliat distance decreased, they approached each other till 

 they became parallel. — This phasnomenon, however, may 

 be nothing more than an optical illusion. 



'' As to the micleus, or the comet itself, it has been found 

 impossible, as yet, even with the aid of the best telescopes, 

 to make observations on its disk, as on that of a soHd body 

 and of determined circumference. We can only discern 4 

 vague circular mass, more luminous than the train, particu- 

 larly towards the centre ; but the verge of which is doubtful, 

 furnishing to the eye no fixed line of demarcation. 



''This mass is without doubt composed of a very subtile 

 substance, as is probably that of all comets. This hypo- 

 thesis receives much support from the fact, that one of 

 these stars, of very considerable magnitude, (the first comet 

 in 1770,) passed and re-passed through the very middle of the 

 satellites of Jupiter without occasioning amongst them the 

 slightest disorder. There is every reason to believe, that the 

 mtcleut of the present comet is nothing more than a conglo- 

 meration of vapours of very little density, so little perhaps as 

 to be transparent. Whether this be the case or not, might be 

 easily ascertained, if those who are in the habit of observing 

 it would watch the moment of its transit alhwart the disk 

 of some star, the rays of which would have sufficient power 

 to perforate it, if transparent. Such a body might very 

 possibly be an incipient world, just past its craseot/s state, 

 and which was to derive solidity from the precipitation and 

 condensation of the matter surrounding it. The succes- 

 sive observation of some comets, in which it may be pos- 

 sible to distinguish the different stages of chaos and pro- 

 gresswe formation, can alone furnish any knowledge with 

 respect to this point." Mnniteur, 4th October. 



To Mr. Tilloch. Glasogw Observ^tm-y, Oct. 7. 



Sir, — I hope the following facts relative to the comet 

 will not be unacceptable to your readers : 



Since my communication to you of the 4th, relative to 

 the comet, announcing the determination of the elements 

 of its orbit made at this establishment, I am happy to per- 

 ceive in the London pa[)crs which arrived to-dav, the result 

 of Eurckhardt's second approximation. The talents of this 

 gentleman as a computer are well known, and highly ap- 

 preciated by the learned world. Between his time of the 

 perihelion passage and ours there is a difference of no more 

 than three days, and the whole period of the comet's revo- 

 lution, I am satisfied, exceeds considerably 100 years. It i§ 

 to be remarked too, that Burckhardt never ventured to gife 



to 



