UNITED STATES. 291 
Magnolia grandiflora, Quercus virens, and the usual English evergreens 
common in the gardens. : . 
Up to about the latitude of 40? or 41? the isotheral lines, or those 
of equal summer-heat, appear to preserve their parallelism in both 
continents with considerable exactness ; but proceeding northward and 
eastward into the New England States, or westward into Canada, we 
find, after passing the forty-second degree,* a remarkable diminution in 
the mean temperature of the warmest season, which now actually 
begins to fall below what it is in the west of Europe under the same 
latitudes, whilst the rigour and duration of winter is according to the 
usual law of decrement more than proportionably increased, except, 
indeed, in the Lake district of Canada (Canada West), where the 
severity of winter is tempered, as we have lately seen, by the con- 
tiguity of those vast bodies of fresh water. Even there the mean heat 
of summer does not exceed that of London by more than 3°33°, and 
of the warmest month by above 4°68°, which with a difference of 8° 30' 
of latitude is very little ; whilst the winter is twelve degrees colder at 
Ancaster than in London. The subjoined table exhibits the mean 
temperatures of Fort Sullivan, Eastport, in the State of Maine, and 
Halifax, Nova Scotia, with that of Bordeaux in France—all three situ- 
ated under the same parallel, and at the sea-level, or scarcely above it. 
P èD [4 es T- Pea 
g E un 
TE Se [che 27 EIS 
a M [-] 
oui as E E pa | OM 
Fort Sullivan...... 44 44 67 E 4172 60°98 22°28 62°96 20°76 
Haba uev | 44 40 63 40 43°16 62°90 25°92 66°56 23°64 
Bordeaux ........ 44 50 0 34 57:02 71°06¢ | 42°98 73:22 | 41°00 
Now we shall find, on taking the means of the climate of Halifax 
and Fort Sullivan, in latitude 44? 40' and 44? 44' (that of Genoa and 
Bologna in Italy), that the result gives us very nearly the climate of 
Stockholm in Sweden, latitude 59° 21’, as given in a former table. 
" = -- |o» E $a 
HIFI ETER 
z FI" | Ss 
Halifax and Fort Sullivan.............- 42:44 | 61-94 | 2410 | 6476 | 22:20 
Stockholm........... x vibus die owed 42°08 60°98 25°52 63°68 23°90 
* Even already at Boston, lat. 42° 21’, the mean heat of summer scarcely reaches 
70°, Fahrenheit (68-90, Mahlmann), two or three degrees less than on the west 
coast of Europe under the same parallel. 
i d — temperature probably a little too high for the rest of France in that 
atitude. 
2P2 
