the pole, has, according to Mackenzie, fifteen land-birds. The South
Shetland Islands, in the same latitude as the southern half of Norway,
possess only some lichens, moss, and a little grass; and Lieut. Kendall
[17] found the bay, in which he was at anchor, beginning to freeze at a
period corresponding with our 8th of September. The soil here consists
of ice and volcanic ashes interstratified; and at a little depth
beneath the surface it must remain perpetually congealed, for Lieut.
Kendall found the body of a foreign sailor which had long been buried,
with the flesh and all the features perfectly preserved. It is a
singular fact, that on the two great continents in the northern
hemisphere (but not in the broken land of Europe between them ), we
have the zone of perpetually frozen under-soil in a low
latitude--namely, in 56 degs. in North America at the depth of three
feet, [18] and in 62 degs. in Siberia at the depth of twelve to fifteen
feet--as the result of a directly opposite condition of things to those
of the southern hemisphere. On the northern continents, the winter is
rendered excessively cold by the radiation from a large area of land
into a clear sky, nor is it moderated by the warmth-bringing currents
of the sea; the short summer, on the other hand, is hot. In the
Southern Ocean the winter is not so excessively cold, but the summer is
far less hot, for the clouded sky seldom allows the sun to warm the
ocean, itself a bad absorbent of heat: and hence the mean temperature
of the year, which regulates the zone of perpetually congealed
under-soil, is low. It is evident that a rank vegetation, which does
not so much require heat as it does protection from intense cold, would
approach much nearer to this zone of perpetual congelation under the
equable climate of the southern hemisphere, than under the extreme
climate of the northern continents.
The case of the sailor's body perfectly preserved in the icy soil of
the South Shetland Islands (lat. 62 to 63 degs. S.), in a rather lower
latitude than that (lat. 64 degs. N.) under which Pallas found the
frozen rhinoceros in Siberia, is very interesting. Although it is a
fallacy, as I have endeavoured to show in a former chapter, to suppose
that the larger quadrupeds require a luxuriant vegetation for their
support, nevertheless it is important to find in the South Shetland
Islands a frozen under-soil within 360 miles of the forest-clad islands
near Cape Horn, where, as far as the _bulk_ of vegetation is concerned,
any number of great quadrupeds might be supported. The perfect
preservation of the carcasses of the Siberian elephants and
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