020 



OBSERVATIONS ON THE ZODIACAL LIGHT. 



No. 2GO. 



DECEMBER 19th, 1854: EVKNING. 



Lit. at 8A., 2D 39' N. : Lin. 117^ 20' W. 

 Sun set 54. Urn. 



Stronger Light, j f~ ^? m '' &c '' to j Diffuse, 6h. 30m. and 7A. 30m. 



Sky very fine for observations. At 6' 1 30' n the Zodiacal Light quite "bright, but with no apparent pulsations, though 



At I' 1 SO'" took b~>un laries again, marked b b, and then thought, 

 I made the following record : 



7 

 * 



h. m. 



At 7 42, 

 7 44, 



45, 

 4fi, 



very bright, 

 dimmed somewhat, 

 bright, 

 very bright. 



I watched carefully to see whether there were any. 

 but not confidently, that there were such changes. 



k. m. 



At 7 31, at a, and dim. 

 7 32, brightening. 

 7 334, tolerably bright, and at b. 

 7 34 bright. 

 7 38, no change. 

 38, very bright. 



*, dimmed apparently ? 



The asterisks mean an interval when no particular record was made. 



I give this, however, with hesitation ; for the changes, if there were such, were very slight ; and I often suspected 

 that what I took to be such, are only the consequence of very intense watching and the imagination, or a change in 

 looking from the darkened part of the sky b.xck to the Zxliaeal Light. At other times I was more certain. 



At 8" 45 1 " the Light was at d ; was dim, but still very distinct and well marked. Tae sky very clear and brilliant 

 this evening. 



7 48, at c. 



7 54, seems to be permanent in brightness, and at c. 



