ICELAND. 29 



of some that have recently overflown into the plains. Iceland appears to have 

 also passed through a glacial epoch, during which the frozen streams descended 

 much lower, and even quite to the sea. The sides of the valleys often show traces 

 of the passage of long- vanished glaciers, and similar indications of their former 

 presence may also he seen on hoth sides of the fiords and river beds. 



Volcanoes. — Geyseus. 

 But " Iceland " might also be called a " Lava-land," whence doubtless the 

 statement of the old chronicler, Adam of Bremen, that the frozen masses, blackened 

 by age, ended by taking fire. The whole island is composed of lands upheaved 

 from the deep in the form of lava and ashes, although most of the rocks have been 

 again engulfed and redistributed in fresh layers of tufa and palagonite. 



As a whole the island is of recent formation, belonging to the tertiary epoch, 

 when the volcanoes began to overflow above the surface. Since then successively 

 submerged and upheaved, Iceland has never ceased to be subject to the action of 

 underground fires. Volcanoes still blaze in many parts of the island, while 

 numerous cones, formerly active, now seemingly quiescent, still betray symptoms 

 of restlessness in the hot springs and vapours at their base. 



The main axis of the volcanic zone runs from the east side of the Vatna- 

 JokuU table-land westwards to the Reykjanes headland, plunging beyond it into 

 the depths of the sea. Along this line are several craters, of which the best known 

 is Hekla, or " Cloak Mountain " (5,095 feet), so named from the clouds of vapour 

 in which its crest is so frequently wrapped. Long regarded, with Vesuvius and 

 Etna, as one of the outlets of the lower regions, this famous volcano is seldom 

 active, twenty instances only having been recorded between 1104, " the year of 

 the great sand fall," and 1875. But its outbreaks are usually of a terrific character, 

 the ashes being wafted hundreds of miles, or falling thickly on the surrounding 

 lands and destroying all vegetation. In 176G the air was completely darkened for 

 a distance of 150 miles, and in 1845 a cloud of dust enveloped a vessel 200 miles 

 to the south of the burning mountain. On that occasion ashes fell on the Fiiroer 

 Isles, and next day blackened the Orkney pastures. After every eruption the form 

 of the mountain is modified, and after that of 1845 it was supposed to have lost 

 200 feet in height. It has been frequently climbed since the first ascension by 

 Bank and Solander in 1770, and before the eruption of 1875 the main crest was 

 pierced by two craters. 



The Katla, or Kotlugja, southernmost of the Icelandic volcanoes, and 36 miles 

 south-east of Hekla, with which it has been often confounded, though now filled 

 with ice, has vomited ashes and torrents of water fifteen times since the year 900, 

 but no lava within the historic period. Of all the eruptions the most disasti'ous 

 was that of 1783, when a rent, running east and west along the base of the Skaptar- 

 Jokull, or eastern escarpment of the Vatna plateau, was entirely charged with lava, 

 incandescent streams burst from the ground, and a vast fiery lake was first formed 

 on the plain west of the Skaptar, and afterwards overflowed in two currents 

 between the hills barring its passige to the coast. Here were formed two oval 



