15 
Ordinary Meeting, November 1st, 1870. 
Rev. William Gaskell, M.A., Vice-President, in the Chair. 
Mr. William H. Johnson, B.Sc.; Mr. Walter Morris, and 
Professor Balfour Stewart, LL.D., F.R.S., were elected Ordi- 
nary Members of the Society. 
Dr. Joule, F.R.S., exhibited a series of curves obtained 
by Dr. Stewart, F.R.S., from the self-recording instruments 
at the Kew Observatory, showing a large amount of dis- 
turbance of the magnetic declination and horizontal force 
during the progress of the Aurora of the 25th October. 
He also showed a curve of the changes which took place in 
the magnetic dip as observed by himself at Broughton. 
The most remarkable valuation occurred during the interval 
from 6h. 15m. to 6h. 23m. G.M.T., when the dip increased 
from 69° 8' to 70° 30'. 
“ On the Aurora Borealis of October 25th, 1870,” by 
T. T. Wilkinson, F.R.A.S. 
On the afternoon of Tuesday the 25th instant the wind 
blew pretty strongly from about W.S.W. at Burnley. The 
barometer suddenly rose from 28'5 to 29T at my residence, 
which is situated about G92 feet above the level of the sea. 
The atmosphere was cloudy most of the day, but soon after 
noon the clouds assumed a very decided cumulo-stratus 
form, and the crests of the huge masses were deeply tinged 
with red. About three o’clock the western portion of the 
sky became mostly free from clouds, with the exception of 
what appeared to be a dense mass of dark brown vapour in 
the low horizon. Immediately above this the sky was of a 
Proceedings — Lit. & Phil. 8oo.— -Yol. X. — No. 3. — Session 1870-71. 
