34] ON THE ORBIT OF THE NOVEMBER METEORS. 271 



to this case, from which it followed that the Earth's action would produce 

 an annual increase of nearly 10" in the longitude of the node. Thus the 

 three planets above mentioned which alone, in the case supposed, sensibly 

 affect the motion of the node, would cause a. motion of about 21" annually, 

 or nearly 12' in 33 '2 5 years. It has been already mentioned that the 

 observed motion of the node is 52"'4 annually, or about 29' in 33 "25 years. 

 Hence the observed motion of the node is totally irreconcilable with the 

 supposition that the periodic time of the meteors about the Sun is 354 - G 

 days. If the periodic time were supposed to be about 377 days, the calcu- 

 lated motion of the node would differ very little from that in the case 

 already considered, while, if the periodic time were a little greater or a 

 little less than half a year, the calculated motion of the node would be 

 still smaller. Hence, of the five possible periods indicated by Professor 

 Newton, four are entirely incompatible with the observed motion of the node, 

 and it only remains to examine whether the fifth period, viz. one of 33'25 

 years, will give a motion of the node in accordance with observation. 



The calculations which have been above described were entirely founded 

 on my own determination of the radiant point. In order to have as secure 

 a basis as possible for the subsequent calculations, I adopted for the position 

 of the radiant point the mean of my own and five other determinations, 

 partly taken from published documents and partly privately communicated 

 to me. These determinations are as follows, the several authorities being 

 placed in alphabetical order : 



E.A. Decl. 



Or with reference to the ecliptic, 



Long. 143 22' Lat. 9 ol'N. 



Starting from this position of the radiant point, and the assumed period, 

 and taking into account the action of the Earth on the meteors as they 

 were approaching it, I obtained the following elliptic elements of their orbit: 



