affected by disturbing causes than those coming from the 
eastward over the continent of Europe, it appeared to me 
that the nature of the law of change of the pressures would 
be best indicated by a comparison of the differences between 
the pressures under north-west and south-west winds. 
These differences are as follows : — 
1858 ... 
... -221 
1864 ... 
... -122 
1859 ... 
... -238 
1865 ... 
... -083 
1860 ... 
... -231 
1866 ... 
... -038 
1861 ... 
... -229 
1867 ... 
... -066 
1862 ... 
... -109 
1868 ... 
... -074 
1863 ... 
... -134 
These numbers indicate a maximum at the end of 1859, a 
minimum in the latter half of 1866, and a secondary maxi- 
mum at the end of 1863, thus presenting a very close agree- 
ment with the results obtained by De la Rue, Stewart, and 
Loewy from actual measurements of the areas of the sun 
spots observed during the period under discussion. 
The mean pressure under all winds is 29 744 inches in 
both periods, but the sum of the differences of the indivi- 
dual pressures from this mean is O’Tooin. in the first period, 
and only 0'530in. in the second. It appeal's therefore that 
the forces which produce the movements of the atmosphere 
are more energetic in years of maximum solar activity than 
in years of minimum. 
Temperature. 
Mean Temp. 
5 years, 
1858-62. 
N 
46-7' 
N.E 
46-7 
E 
48-1 
S.E 49-5 
S 50-8 
S.W 
51-1 
W 
48-8 
N.W 
. ... 46-6 
Mean Temp. 
6 years, 
1862-68. 
Difference. 
. 46-8° 
... -0'1° 
46 - 5 
... +0-2 
. 50-4 
... -2-3 
. 52-2 
... -2-7 
. 52-3 
... -1-5 
. 50-7 
... +04 
48-8 
o-o 
. 47-1 
... -0-5 
In the first period the maximum temperature occurs 
under winds from south-west, and in the second period 
under winds from about south-south-east. The greatest 
