The quantity of matter ejected by the rent and shivered mountain was computed at fifty or sixty thousand millions of cubic yards. The molten lava flowed in a stream which in some places was twenty to thirty miles in breadth, and of enormous thickness; a seething, hissing torrent, which filled the beds of rivers, poured into the sea nearly fifty miles from its points of eruption, and destroyed the fishing on the coast. Some of the island-rivers were heated, it is said, to ebullition; others were dried up; the condensed vapour fell in whirls of snow and storms of rain. But dreadful as was the eruption itself, with its sublime but awful phenomena, far more dreadful were its consequences. The country within its range was one wide ghastly desert, a fire-blighted wilderness; and, partly from want of food, partly owing to the unwholesome condition of the atmosphere, no fewer than 9336 men,[10] 28,000 horses, 11,461 cattle, and 190,000 sheep, were swept away in the short space of two years. Even yet Iceland has scarcely recovered from the blow. At the northern end of the great central valley the focus of igneous phenomena is found in a semicircle of volcanic heights which slope towards the eastern shore of the Lake Myvatr. Two of these are very formidable,--namely, Leirhnukr and Krabla on the north-east. After years of inaction, they suddenly broke out with tremendous fury, pouring such a quantity of lava into the Lake Myvatr, which measures twenty miles in circuit, that the water was in a state of ebullition for many days. On the sides of Mount Krabla, and at the base of this group of mountains, are situated various caldrons of boiling mineral pitch, the ruined craters of ancient volcanoes; and from their depths are thrown up jets of the molten matter, enveloped in clouds of steam, and accompanied by loud explosions at regular intervals. But the most singular phenomena in this singular country, where frost and fire are continually disputing the pre-eminence, are the _Geysers_, or eruptive boiling springs. These all occur in the trachytic formation, are characterized by their high temperature, by holding siliceous matter in solution, which they deposit in the form of siliceous sinter, and by evolving large quantities of sulphuretted hydrogen gas.