APPENDIX. 



Zl 



and in appearance like the brighter portion of an aurora borealis, 

 occupies a place in the zodiacal light which is quite accurately 

 opposite to the moon's place ; and, night after night, as the moon 

 advances, this luminous spot rises among the stars, so as still to 

 keep opposite to the moon ; as though the somewhat more dense 

 portion of the further end of the oval (as respects the moon) 

 were thus more conspicuous than the other portions then in view: 

 mid then, the upper extremity is broad, and not so sharply pointed 



as is true in Case 1, as though 

 for the reason assigned in Case 

 2. 



Case 4. After the Last Quarter 

 and before the New Moon, the Zo- 

 diacal Light of the evening is again 

 faint, as it was before the First 

 Quarter ; as though the illumina- 

 tion were wholly of that part of 

 the girdle beyond the region near 

 the longer axis. 



Case 5. When the moon is 

 nearly in Quadrature, it would seem 

 that the Zodiacal Light must appear 

 short and bright, if apparent at all, 

 after the twilight of the evening; or 

 before twilight in the morning. For 

 then the sun's light would be transmit- 

 ted by a short course through the most 

 curved, and probably more dense por- 

 tions, near to one end of the longer 

 axis of the oval. 

 These are phenomena to which I invite special attention in the 

 way of renewed and careful observation. 



I should have said that in stating these five cases of appear- 

 ances of the zodiacal light, I am contemplating the supposition 

 that the girdle encompasses the moon. 



(29) 



