S6 
M. Humboldt on Isothermal Lines, 
Observations of 
M. Bouvard. 
Mean Temperature 
Of the 
Year. 
Of Win- 
ter. 
Of Sum- 
mer. 
Of Ja- 
nuary. 
Of Au- 
gust, 
Of Oc- 
tober. 
Paris, 1803, 
51M 
36°.7 
67°.6 
34°.3 
67°.6 
50°.5 
1804, 
52.0 
41.0 
65.5 
43.9 
64.6 
52.7 
1805, 
49.5 
36.0 
63.1 
34.9 
64.8 
49.3 
1806, 
53.4 
40.6 
65.3 
43.0 
64.6 
51.8 
1807, 
51.4 
42.3 
67.8 
36.1 
70.5 
54.3 
1808, 
50.5 
36.7 
66.2 
36.3 
66.6 
48.2 
1809, 
50.9 
40.5 
62.4 
40.8 
64.2 
49.6 
1810, 
50.9 
36.5 
63.3 
30.6 
63.7 
52.9 
1811, 
52.7 
39.2 
65.1 
26.6 
63.7 
57.6 
1812, 
49.8 
39.6 
63.1 
34,7 
64.2 
51.1 
1813, 
49.8 
36.1 
61.7 
32.5 
62.6 
53.1 
Mean of these 11 years. 
5r.i 
38°.7 
64°.0 
36°.6 
65=. 1 
51°.9 
At Geneva, the mean temperatures of the summers were, 
from 1803 to 1809,— 
Mean Temp 
Years. of Summers. 
1803, - 67°.3 
1804, - 65.0 
1805, - 
1806, 65.7 
1807, - 68.2 
1808, - 62.9 
1809, - 63.0 
Mean of seven years, 64°. 9 
M. Arago has found, that in the two years 1815 and 1810, 
the last of which was so destructive to the crops in a great part 
of France, the difference of the mean annual temperature was 
only 2®, and that of the summer 3°. 2. The summer of 1816 
at Paris was 59°. 9, 4°. 7 below the mean of the former. From 
1803 to 1813, the oscillations round the mean did not go be- 
yond — 2°.9, and +3°4. 
In comparing places which belong to the same system of cli- 
mates, though more than eighty leagues distant, the variations 
seem to be very uniform, both in the annual temperature and 
that of the seasons, although the thermometrical quantities are 
not the same. 
