fome luminous Arches . 37 
the hind-glafs of the carriage, and law the fame luminous ap- 
pearance in the eaft. This roufed my attention ; and imme- 
diately letting down the glades, I looked out and perceived 
a broad arch of a bright pale yellow, arifing between Arfturus 
and Lyra, about the right leg of Hercules, and paffing confident 
b]y to the fouth ot the zenith, its northern border being 
a little fouth of Pollux, and defending to the horizon near 
Orion, which was then fetting. 
This arch feemed to me to be about 15 degrees in breadth, 
and was of fuch a varied denfity, that it appeared to confift of 
fmall columns of light, which had a fenfible motion. 
I had fcarcely viewed this arch above ten minutes, when I 
faw innumerable bright corulcations, (hooting out at light 
angles from its northern edge, which was concave, and elon- 
gating themfelves more and more till they had nearly reached 
the northern horizon. As they defended, their extremities 
were tipped with an elegant crimfon, fuch as is pioduced by 
the eledlric fpark in an exhaufted tube. After fome time this 
aurora borealis ceafed from fhooting, and formed a range of 
beautiful yellow clouds, extending horizontally about a cju al- 
ter of a circle. - 
The eaftern leg of this arch feemed to me to make an angle 
of about 60 degrees with the horizon \ and when I traced out 
the courfe of the arch upon the celeftial globe, 1 judged that 
the center of it muft have palled about 30 degrees to the fouth 
of the zenith. The crown of the arch appeared convex towards 
the fouth, and concave towards the north. The greateft part 
of the aurora borealis which darted from this arch towards 
the north, as well as the cloudTike and more ftationary aurora , 
were fo denfe, that they hid the ftars from view. The moon 
was eleven days old, and fhone bright during this fcene, but 
