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 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. 



PiiocEEDTNGS— Lit. & Phil. Society— No. 4.— Session, 1860-61. 



