Appearance of Comet II. at Paris. 123 



been able to repeat the observation on another jet which I also 

 saw again on the evening of the same day., I give a summary 

 which will truly interpret the phenomena. ( ff Voici sommaire- 

 ment quelle serait la veritable interpretation des phenomenes.") 



The nucleus of the comet emits in the direction of the sun 

 a vaporous jet, whence seem to escape particles of cometary 

 matter as a jet of steam escapes from a machine. This jet pre- 

 serves, during a certain time, a rectilinear form, which seems to 

 indicate a considerable force of projection emanating from the 

 nucleus. Soon afterwards it bends slightly, and presents the 

 appearance of a curved cone, bearing much resemblance to a 

 horn of plenty, as usually represented. At this time the gaseous 

 particles accumulate at that extremity of the jet nearest to the 

 sun, under the form of rounded clouds ; and this appearance 

 seems to indicate that at this distance from the nucleus the 

 force of projection is conquered by a resistance which is opposed 

 to it. 



Some hours later, this luminous jet takes a diffused aspect, 

 and shows that the nucleal emission has ceased to go forth in 

 this direction. At the moment when it commences to change 

 its form, and at an angle of position inclined about thirty de- 

 grees towards the east, the first traces of a new ray may be 

 seen, its development presenting the same phenomena as those 

 which preceded it. Sixteen hours later, in the direction of 

 those first traces visible on the previous day, may now be ob- 

 served a new ray, and this latter continuing in this interval of 

 time to lose shape ("se deform er"), appears dispersed in the 

 hemispherical envelope like a fog, scarcely preserving any traces 

 of its original form and direction. 



In its successive transformations this new ray offers in the 

 sequel the same appearances as that parallel to the radius vector. 



Since the epoch of the comet's perihelion passage, the jet 

 which nearly corresponded to the radius vector inclined gradually 

 westward to that point to which the other ray tended on the 

 30th of August, precisely in the direction opposite to the tail 

 of the comet. 



