The remarkable contrast is pointed out
between the climate and cultivation of the east and west sides of the
mountains of Sweden and Norway. Barley ripens as far north as the 70th
degree, in latitudes whose mean temperature is below the
freezing-point; while in Switzerland, corn ceases to ripen at 9
degrees above the same point, and in the plateaux of South America, at
22-1/2 degrees--a fact which goes to shew, 'that the growth of grain
is much more dependent on the summer temperature than on the annual
mean. The long summer days of the polar regions afford a very brief,
but a comparatively exalted summer heat.' It is, however, only the
barley which ventures so far north: the limit of rye is 67 degrees, of
oats, 65 degrees, of wheat, 64 degrees, on the west side of the
peninsula, and from 1 to 2 degrees less on the east. In Southern
Norway, the spruce-fir ceases to grow beyond the line of 2900 feet
above the sea-level; while in Switzerland, it is commonly met with at
the height of 5500 feet, and in some situations, 7000; shewing that
the influences which affect the growth of grain do not similarly
affect that of trees--proximity of the sea decreases the summer
temperature. Again: 'In Scandinavia the tree-limit is indicated by the
birch; in the Alps, by firs. The two lower mountain zones of the
Alps, the regions of the beech and the chestnut, do not exist in the
Scandinavian mountains.
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