48 OBSERVATIONS ON THE ZODIACAL LIGHT, 



No. 24. 

 JULY 5th, 1853 : EVENINO. 



Lat, at S/i. 30m., 30 47' N. i Lon. 133^ 3:>' E. 



SSun srt 7/i. 

 Stronger Light at 8A. 30m. Diffuse at 8A. 30m. 



90 90 



9 30 



I watched carefully, this evening, to see how the Zodiacal Light would first disclose itself to the sight. The eve- 

 ning good and clear. After the purple sunset-light was gone, a bright, steel, light succeeded along the horizon, 

 seemingly common twilight. This remained ; but at 8 h its horizontal limits had contracted so, as to extend but 17 

 S. and 55 N. of Venus,* then near setting. Its height was 20 ; towards its southern end this light began grad- 

 ually to slope upward; and also, on the sky above, an elongated, dim, milky light, gradually impressed itself. 

 At first it was doubtful; then less so; then, at 8 h 15 m , it was decidedly the Zodiacal Light reaching as high as 94 

 Leonis Majoris, and having the usual outlines of this Light. It was, however, dim above. At 8 h 30 m the whole was 

 clearly marked and distinct, and I was able to get outlines. At 9 h 30 m there was no Stronger Light ; at 9 b this was 

 not strong, but stronger than the rest. At 10 h 30 m there was only a slight suffusion of light between the boundary 

 of 9 h 30"' and the horizon. The dotted line a a shows the boundary of "the dimmed sky" as before. 



At 8 h 30 m the bright sky on the right, into which the Zodiacal Light seems to run (if it is not a continuation of 

 it), extended 170 in width along the horizon till it reached 75 N. from Regulus: its upper edge thus extended 

 within 15 of the polar star itself. 



Vrniis had then 25 of N. declination (gcomitrir). 



