Ill 



Ordinary Meeting, March oth, 1872. 

 E. W. BiNNEY, F.R.S., F.G.S., President, in the Chair. 



" On Changes in the Distribution of Barometric Pressure, 

 Temperature, and Rainfall under different Winds during a 

 Solar Spot Period, by Joseph Baxendell, F.R.A.S. 



In my paper " On Periodic Changes in the Magnetic Con- 

 dition of the Earth, and in the Distribution of Temperature 

 on its Surface;" read March 8, 1864, I endeavoured to 

 account for some of the phenomena therein described by 

 assuming that variations in the magnetic condition of the 

 earth produce corresponding variations in the direction and 

 velocity of the great currents of the atmosphere ; and some 

 time afterwards in considering this hypothesis more care- 

 fully it appeared to me that if, as is generally supposed, 

 magnetic changes are intimately connected with the dis- 

 turbances which take place in the solar photosphere, their 

 influence upon the atmosphere ought to be indicated by 

 variations in the distribution of barometric pressure, tem- 

 perature, and rainfall under diflferent winds corresponding 

 to the variations of solar spot frequency. Fortunately the 

 means of at once testing the soundness of this view were at 

 hand in the valuable tables numbered XYI. and XYIII. in 

 the volumes of the "Radcliffe Observations," which show 

 for each year the relations between barometric pressure, 

 temperature, and rainfall under different winds at Oxford. 

 I therefore extracted from these tables, and arrangfed in 

 order, the mean annual barometric pressures, mean tempe- 

 ratures, and amounts of rainfall under different winds for 

 the ten years 1858-67, and on carefully examining the table 

 thus formed I found that changes had taken place in the three 

 elements which corresponded very closely in the times of their 

 maxima and minima with those of solar spot frequency. 



The mean length of a solar spot period is about 11 years 

 and 5 weeks, and as the volume of " Radcliffe Observations" 

 for 1868 has been published since I formed the ten years 

 table, I have included the mean results for that year in the 

 following table, which thus represents the changes which 

 took place through a complete solar spot period. 



Proceedings — Lit. & Phil. Soc. — Yol. XI. — No. 11.— Session 1871-2. 



