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THE POPULAR SCIENCE MONTHLY. 



Iceland is an elevated plateau about two thousand feet high, with 

 a narrow marginal habitable region sloping gently to the sea. The 

 elevated plateau is the seat of every species of volcanic action, viz., 

 lava-eruptions, solfataras, mud-volcanoes, hot springs, and geysers. 



These last exist in great numbers ; more than one hundred are found 

 in a circle of two miles diameter. One of these, the Great Geyser, 

 has long attracted attention. 



The Great Geyser is a basin or pool fifty-six feet in diameter, on 

 the top of a mound thirty feet high. From the bottom of the basin 



