[ 47 2 ] 
XII. A Letter from John Huxham M. D. 
F. R. S. to C. Mortimer M. D. Seer . R.S. 
containing Obfervations on the Northern 
Lights, feen Feb. 15 and 16, 1749-50. 
'Dear Sir , 
Read June OU have herewith an Account of 
J_ two uncommon Fhtenomena, which 
I obferved laft February . 
Feb. 15, 1749-yo, in the Evening there was a very- 
vivid Northern Light, which darted forth feveral 
beautiful, crimfon, and fiery-colour’d Rays ; Wind 
NW^N I, Barometer 30.2 yo Minutes part 8 a 
furprifingly bright and exceedingly white Arch, about 
the Breadth of a common Rainbow, appear’d in 
the Heavens, extending nearly from Eaft to Weft; 
it reach’d within 5 or 6 Degrees of the Weftern 
Horizon, and ended about 8 or 10 above the Eaftern. 
It palled cxa&ly between Cajior and Follux , and 
diredly over Aldebaran, which appeared plainly thro* 
it. Near the Top of the Arch feveral very lucid, 
white, fhort, vibrating Columns were attached to 
it ; none of them feem*d above 6 or 7 Degrees long, 
and did not appear to communicate in the lead 
with the Aurora borealis. The inclofed Figure (fee 
Tab.I. Fig. y.) fomewhat reprefents it. About ph 
12' the Arch vanished ; but feveral white, bright, cor- 
rufeating Nubecula remain’d here and there in the 
Zodiac for 12 or 15 Minutes longer. The Aurora 
borealis continued more or lefs till Midnight : The 
next Morning the Wind was E.i x , Barom. 30.1. 
