426 OBSERVATIONS ON THE ZODIACAL LIGHT. 



No. 213. 



SEPTEMBER ]3th, 1854: EVENING. 



Lat. at PA., 23 4' N". : Lon. 1 10 47' E. 



Sun set at Gli. "Am. 

 Stronger and Diffuse Light at 7h. 15m. and lit. 45m. 



Sky bright and clear. Paid particular attention to the off-shoot a a, of the Stronger Light ; but its character, as 

 apparent Zodiacal Light, was not so striking as at the same hour last night ; there being now a little haziness along 

 the horizon. Still, the sudden termination of this Light on the right hand was very obvious ; the horizon, both on 

 right and left, beyond the limits marked, being dark. I paid particular attention, also, to the boundaries of the 

 Diffuse Light, and took them carefully. The Stronger Light was strongest up to the zigzag line at x, and was not 

 well marked at its upper end. Its old course down the ecliptic was distinct, notwithstanding the adjunct Light 

 towards l> b. I neglected to take (his last at 7 h 45. 



I was tolerably certain that there were pulsations. The dimming was very rapid ; but the brightening up again 

 was so very slow and gradual, that it was nearly, if not quite, impossible to note it reliably. I made the following 

 notes : 



7*. m. 

 At 7 35, almost gone. 



7 43, dim. 



7 47, bright again. 



h. m. 

 At 7 28, bright. 



7 29i, dimmed. 

 # # # 



7 34, bright. 



7 34^, sensibly dimmer. 



The asterisks designate periods during which I was not certain enough to feel authorized to mark changes, though 

 they seemed to be going on. 



At 8 h 10 m the Light was still very distinct, but its outlines could not be got reliably. At 9 h , nothing more could 

 be fully made out, though the Diffuse Light seemed to be still evident. 



