4Q THE OESYERS. 



nally this mound is hollow, presenting a basin of about one hundred and 

 fifty feet in circumference, which is usually filled to the depth of about 

 four feet with boiling water, beautifully clear and crystaline. In the 

 middle of this basin, a pipe or funnel, about ten feet in diameter, 

 but wider at the top, descends perpendicularly in the earth, to the depth 

 of nearly eighty feet. It is this tube that is the vent of this subterranean 

 action of fire and water. The bottom and sides of the basin, within the 

 mound, are covered with whitish siliceous incrustations; rendered 

 perfectly smooth by the constant action of boiling water. Two small 

 channels from the sides of the basin open, and allow almost constant passage 

 to some of the water. This water, still hot, and strongly impregnated 

 with mineral matter, on leaving the mound through a turfy kind of soil, 

 and by acting on the peat, mosses, and grass, gradually produces some 

 of the most beautiful specimens of petrefaction ; leaves of the birch, and 

 other stinted trees, which grow in that inhospitable climate, are also found 

 incrusted, so as to appear as of white stone, yet still preserving, not 

 merely their general form, but their minutest fibres, unaltered. 



The eruptions of the great Geyser occur at irregular intervals : low 

 reports, and slight concussions of the ground, give the first signal of 

 coming violence. These symptoms are succeeded by a few jets, thrown 

 up by the pipe or funnel, in the centre of the basin; and then after a 

 pause of a greater or less number of minutes, a rumbling noise is heard 

 underground; louder reports succeed, and concussions, strong enough 

 to shake the whole mound ; in the interior of which, the water boils with 

 increased violence, and overflows the edges of the capacious basin. 

 Other reports soon follow, being louder and more rapid than the pre- 

 ceding, and not unlike the discharge of a piece of artillery. Then, with 

 an astounding roar, and immense velocity, the water rushes through the 

 pipes, and rises into the air, in irregular jets, which are surrounded 

 and almost concealed by accompanying volumes of steam. To these 

 first jets, loftier and more defined ones succeed, and these are generally, 

 a central or main jet, presenting a column of boiling water, from nine 

 to twelve feet in diameter, from fifty to seventy feet in height, on an 

 average. Sometimes the main jet exceeds a hundred feet in height, and 

 other geysers are said to throw water, though not in such a volume, to a 

 greater elevation. As the jets of the great geyser issue from the central 

 pipe, the water in the basin, near the pipe, is raised about a foot and a 

 half, and as the columns descend into the orifice, from whence they are 

 ejected, the water every where overflows. Unlike the eruptions of fire, 

 from the crater of a volcano, which often last for days, without any 

 apparent diminution or pause, these boiling fountains seldom play 



