1 22 
PHYSICAL AND MATHEMATICAL SECTION. 
November 7th, 1871. 
Alfred Brothees, F.R.A.S., Vice-President of the Section, 
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. 
[This paper was afterwards read at the Ordinary Meeting 
of the Society held March 5, 1872. See p. 111]. 
December 5th, 1871. 
Thomas Carrick, Esq., in the Chair. 
“ On the Distribution of Rainfall under different Winds, 
at St. Petersburg, during a Solar Spot Period,” by Joseph 
Baxendell, F.R.A.S. 
In the paper which I read at the last meeting of the 
Section it was shown that, at Oxford, changes take place 
in the relative amounts of rainfall under different winds in 
a period corresponding with that of solar spot frequency. 
Thus in the years when the number of groups of solar spots, 
as observed by Schwabe, was above the average, the amount 
of rainfall under west and south-west winds was greater 
than that under south and south-east winds, while in the 
years when the number of groups of solar spots was below 
the average the reverse of this took place, the amount of 
rainfall under west and south-west winds being less than 
that under south and south-east winds. The hypothesis 
which led to the investigation requires, however, that great 
diversity should exist in the relative amounts of rainfall 
under different winds at different stations. While at some 
the distribution will be similar to that at Oxford, at others 
it will be of an opposite, and in others again of an inter- 
mediate character; but, whatever may be the nature of the 
distribution at any station, the changes to which it will be 
subject will take place in a period identical with the solar 
spot period. In some localities the changes will be so slight. 
