Dlstrihuiion qf Heat over the Globe. ^ S61 
derations which I pointed out in my work on Mexico are to 
be added the observations of Captain Lewis, and some other 
Anglo-American travellers, who have passed the winter on the 
banks of the Columbia. In New California, they cultivate 
with success the olive, along the canal of Santa Barbara, and 
the vine from Monterey to the north of the parallel of 37% 
which is that of Chesapeake Bay. At Nootka, in the Island 
of Quadra and Vancouver, and almost in the latitude of La- 
brador, the smallest rivers do not freeze before the month of 
January. Captain Lewis saw the first frosts near the embou- 
chure of the Colombia, only on the 7th of January, and the 
rpst of the winter was rainy. Through 122° 40' of west long, 
the isothermal line of 50° Fahr. appears to pass almost as in 
the Atlantic part of the Old IVorld, at 50° of lat. The west- 
ern coasts of the two worlds resemble one another to a certain 
point -f*. But these returns of the isothermal lines do not extend 
beyond 60°. The curve of 32° Fahr. is already found to the 
south of the Slave Lake, and it comes still farther south in 
approaching Lakes Superior and Ontario. 
In advancing from Europe towards the east, the isothermal 
lines again descend J, the number of fixed points being few. 
We can only employ those which are made in places whose 
known elevation allows us to reduce the mean temperatures to 
the level of the sea. The few good materials which we possess, 
have enabled us to trace the curves of 32° and 55°. 4. We know 
even the nodes of the latter curve round the whole globe. It 
* Essai Politique sur la Nouvelle Espagnet tom. ii. p. 440, 478, 509. 
On account of the influence of west and south-west winds. See Dalton’s 
Meteor, Observ. p. 125. I 
$ In comparing places from the west to the east, and nearly under the same 
parallel, we find. 
West. 
Lat. 
Mean 
Temp. 
East. 
Lat. 
Mean 
Temp. 
St Malo, 
48® 
39' 
54®.5 
Vienna, 
48° 
13' 
50®.5 
Amsterdam, 
52 
21 
53 .4 
Warsaw, 
52 
14 
48 .6 
Naples, 
40 
50 
63 .3 
Pekin, 
39 
54 
54 .9 
Copenhagen, 
55 
41 
45 .7 
Moscow, 
Petersburgh, 
55 
46 
40.1 
Upsal, 
59 
52 
41 .9 
59 
56 
38 .8 
The elevation of Pekin is inconsiderable. That of Moscow is 984 feet. The 
absolute temperature of Madrid, to the west of Naples, is 59® ; but the city iffi 
elevated 1978 feet above the level of the sea.— H. 
