15 
Ordinary Meeting, November 13th, 1860. 
Dr. Fairbairn, F.R.S., &c., Vice-President, in the Chair. 
The Chairman made some obvervations respecting experi- 
ments conducted in the Dukinfield Coal Pit, for the purpose 
of determining the rate of increase of temperature below the 
earth’s surface. He stated that from these experiments a 
mean increase of one degree Fahrenheit for every seventy-one 
feet had been arrived at ; and he promised on a future occasion 
to communicate the details of the determinations. 
A Paper was read by Mr. Baxendell, F.R.A.S., entitled, 
“ On a System of Periodic Disturbances of Atmospheric 
Pressure in Europe and Northern Asia.” 
Whilst engaged some time ago in an investigation of the 
phenomena of the general disturbances of the atmosphere, the 
Author had been led to conclude that moderately accurate 
determinations of the sums of the oscillations of the barometer, 
for given periods, at different places on the surface of the 
earth, would afford valuable information respecting the nature 
of these disturbances, and, at the same time, throw additional 
light upon the causes by which they are produced. Determi- 
nations of the statical element of mean pressure are obviously 
of very limited use in an inquiry of this kind ; but notwith- 
standing the importance of the subject, meteorologists have 
hitherto generally neglected to ascertain, even approximately, 
the values of the dynamical element as represented by the 
sums of the oscillations of the mercurial column. In none of 
the many volumes of observations which issue from the public 
observatories of this country and the continent has the Author 
yet seen any attempt made to deduce the values of this 
element. 
Proceedings — Lit. & Phil. Society— No. 4.— Session, 1860-61, 
