 The igloo, a temporary
winter hunting shelter to the Alaskan Eskimo does, in fact, melt inside, but not to
a great extent.
The snowflakes falling outside of the igloo, in the harsh Alaskan
winter, quickly melt when they land on its roof, and provide a
replacement layer of insulation for the igloo. The ongoing freezing
and re-freezing of the igloo, hardens it, and transforms the blocks
of snow the Eskimos used in the construction process into a solid,
icy, domed refuge. The igloo can now withstand the weight of a
massive polar bear, should one happen
along and have the urge to play "king of the mountain."
The initial freezing and re-freezing of the igloo takes place at
end of the igloo's construction. First, the men must dig a trench
into a fresh snow- drift, and, using their knives, cut blocks of
snow from it that are specifically shaped to face inward when fully
laid out. They then lay the blocks on their edges to form a circle,
cutting them to size as they go, so that the end result will be a
narrowing spiral. They cap the igloo by dropping a keystone, or block with edges cut wider above
than below, into the remaining gap in the roof, and "grout" the gaps
between blocks of snow with additional snow.
The men then call in the resident expert, the Eskimo woman, to
put the finishing touches on the igloo. Armed with her whale blubber lamp, she enters the structure,
lights her lamp to the highest possible setting, beats a hasty
retreat, and seals the entrance with a block of ice. Inside the
igloo, the snow on the roof begins to melt but, because of its domed
design, the water melts down the sides of the igloo, and soaks the
blocks of snow. When the blocks are almost completely saturated with
water, the Eskimo woman returns, douses
her blubber lamp, and allows the frigid outside air to rush in,
transforming the fragile snow structure into one of hard, solid
ice.
The igloo is now prepared for its temporary tenants, whose body
heat, combined with the warmth of one to two blubber lamps, maintain
its interior at approximately 55°F. Not until the winter ends, and
the exterior temperature rises, does the igloo begin to melt.
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note:
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igloo: （因紐特人的）圓頂冰屋
Eskimo: 愛(ài)斯基摩人
polar bear: 北極熊
keystone: 拱頂石
whale blubber lamp:
鯨脂燈
douse: 熄滅 | |
