113 



According to the observations of Schwabe the numbers 

 of groups of solar spots which occurred in the years 1858-68 

 were as follows : — 



No. of No. of 



Year. Groups. Year. Groups. 



1858 188 1864 130 



1859 205 18G5 93 



1860 211 1866 45 



1861 204 1867 25 



1862 160 1868 101 



1863 124 



The mean number is 135, and therefore it appears that 

 during the five years 1858-62 the frequency of solar spots 

 was above the average, and during the six years 1863-68 it 

 was below. In order then to ascertain the effects of changes 

 of solar activity upon the distribution of barometric pres- 

 sure, temperature, and rainfall under different winds, the 

 above table was divided into two tables, the first com- 

 prising the results for the five years 1858-62, when the 

 number of solar spots was above the average, and the second 

 those for the six years 1863-68, when the number of spots 

 was below the average. The means of the numbers under 

 each wind in both tables were then determined, and a com- 

 parison of the two sets of results thus obtained showed, for 

 each element, the nature of the changes which had taken 

 place. 



Barometric Pressure, 



The mean pressures under different winds for the two 

 periods, and their differences, are as follows : — - 



Mean Pressure Mean Pressure 



1858-62. 1863-68. Difference. 



N 29-859 29-849 +0^-010 



N.E 29-890 29-801 +0-089 



E 29-791 29-728 +0-063 



S.E 29-672 29-615 +0057 



S 29-635 29-652 -0-017 



S.W 29-604 29-719 -0-115 



W 29-684 29-789 -0-105 



N.W 29-810 29-805 +0-005 



