To many of us, building a house of ice doesn’t sound too good. One might wake up from a good night’s sleep to see it melted. All these things don’t matter to Eskimos, who live in north Canada, Greenland and Alaska. They build igloos or houses of ice knowing that they will not melt. At least, not till winter passes by. The reason is that the walls are made in a special way so that they become rock hard.
Building an igloo takes about a couple of hours. It is made in the shape of a dome. First, they cut a trench or pit. It is about 1.5 metres long and 50 centimetres deep in the snow. Then they cut blocks of snow from the trench and place it around the trench in a circle. These blocks are shaped in such a way that they lean inward when one is kept on the other. Their edges are trimmed so that the circumference slowly reduces, forming a dome-shaped structure. The blocks are cut from the inside of the house as the man works. Then a big block, which is wider than the rest, is put on top. All the cracks are filled with soft snow.
After the main structure has been built, the woman gets into the house and lights a lamp. She lets it burn till it is really hot. Then she closes the door with a block of ice making the structure airtight. This way the lamp’s heat is trapped inside and the snow begins to melt. But, because the dome’s roof is curved, it does not drip. Instead, it gradually soaks into the blocks so that they become wet.
When the blocks are sufficiently wet, she puts out the lamp and opens the door, letting in a gush of cold air. This draught of biting cold air freezes the melting snow and the fragile structure made of ice blocks becomes a strong dome of ice. It becomes so strong that a polar bear can crawl on it without breaking it.