222 Appearance of Comet II. at Paris. 



To give an idea of these luminous expansions turned to- 

 wards the sun, we may state, that the principal ray measured 

 on the 17th, towards eleven o' clock in the evening, an angle of 

 two minutes. That is to say, it extended beyond the nucleus 

 over a space four times greater than the diameter of the earth. 



On the same evening, the comet presented to the eye the 

 appearance of a nebulous star, of a brightness nearly equal to 

 that of the star Gamma in the constellation of the Little Bear. 

 Nevertheless, the tail, on account of its dimness, could scarcely 

 be distinguished to the length of a degree. 



THIRD NOTE FROM M. CHACORNAC ON THE SECOND COMET 



OF 1862. 



The comet continues to present interesting phases in the 

 development of its aigrettes. 



In attentively following the form of the jets which escape 

 intermittently, I have just remarked a fact still more strange 

 than those described in the preceding notes. In the latter I 

 pointed out that one of these jets or rays, darted firstly in the 

 direction of the sun, was afterwards turned aside in a direction 

 opposed to the movement of the comet, so that on the next day 

 it could be observed making an angle with the direction of the 

 previous day (" avecla direction de la veille"). 



The fine weather which has lately come having permitted 

 me to follow during whole nights the mode of transformation 

 of different vaporous jets which have been disengaged from the 

 nucleus, I will recount the phenomena in the true order of their 

 succession. 



Firstly, it is necessary to say, that the ray of the previous 

 day, directed nearly to the sun, was not that which one saw 

 next day inflected in a direction opposite to the movement of 

 the comet ; the latter was a new ray emitted by the nucleus in 

 this very direction. 



From the 17th to the 20th of August, pondering on the 

 forms presented by the rays, alternately rectilinear and clear, 

 or curved and diffused, I already felt doubtful of the identity of 

 these two jets ; but, following the opinion of Bessel about Hal- 

 ley's Comet, I believed in some analogous movement of the 

 aigrette of the present comet, all its other phenomena seeming 

 to confirm this analogy. 



Three nights in which the sky was completely overcast, left 

 me in this belief. On the 22nd of August, the sky having 

 again become clear, I persevered from nine in the evening till 

 four next morning in following the slightest variations per- 

 ceptible in a jet directed to the sun, and I believe I have de- 

 tected its true nature. 



In the night from the 25th to the 26th of August, having 



