[ ] 
VI. Extract of a Letter from J. Franklin, Efq. relative to <t 
luminous Arch . Communicated by Sir Joieph Banks, Bart . 
P. P. 5 . 
• Read December 14, 1786. 
Blockley, Feb. 25, 1786. 
IT CANNOT help giving you a line to let you know, that I 
JL obferved a very odd appearance in the heavens on Monday 
evening iaft, about a quarter before nine o’clock. Happening 
to go out of the houfe, I was very much iurpriled to fee a 
N white light, broader than a rainbow, pals acrols t lie heavens 
from eaft to weft. At firft I thought it might be a lunar rain- 
bow ; but, after fome moments refleftion. 1 knew it could not 
be from its fituation. I now began to obferve its iituajtion and 
form more minutely. It ./as a bright white light, about 
5 degrees wide in the zen ih, and gradually coming to a point 
both ways. The eaftern point terminated between Arfturus 
and the bright ftar m the Knee of Bootes. "I he weftern point 
came nearly to the ftar marked a in the Whale’s mouth. Tne 
iouthcrn fide of the light was about 5 degrees above Caftor, 
palling eaftvvard above Berenice’s hair, and weftward near 
Aldebaran, and through the Hyades. I obferved it till nine 
o’clock. Aldebaran was fouth of it when I firft faw it ; but it 
palled, and got north, before nine o’clock. At five minutes 
paft nine, no. more of it was to be feen. It gradually went 
oft in a few minutes. The iky was very clear from clouds, and 
the ftars fhone bright, 
