The universal geography : earth and its inhabitants

ICELAND. 20of some that have recently overflown into the plains. Iceland appears to havealso passed through a glacial epoch, during which the frozen streams descendedmuch lower, and even quite to the sea. The sides of the valleys often show tracesof the passage of long- vanished glaciers, and similar indications of their formerpresence may also he seen on hoth sides of the fiords and river heds.Volcanoes.— Geysei;s.But " Iceland " might also he called a " Lava-land," whence douhtless thestatement of the old chronicler, Adam of Bremen, that the frozen masses, blackenedby age, ended by taking fire. The whole island is composed of lands upheavedfrom the deep in the form of lava and ashes, although most of the rocks have beenagain 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 successivelysubmerged and upheaved, Iceland has never ceased to be subject to the action ofunderground fires. Volcanoes still blaze in many parts of the island, whilenumerous cones, formerly active, now seemingly quiescent, still betray symptomsof 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-Jokull table-land westwards to the Beykjanes headland, plunging beyond it intothe depths of the sea.is Hekla, or " Cloak Mountain " (5,095Along this line are several craters, of which the best knownfeet), so named from the clouds of vapourin which its crest is so frequently wrapped. Long regarded, with Vesuvius andEtna, as one of the outlets of the lower regions, this famous volcano is seldomactive, twenty instances only having been recorded between 1104, " the year ofthe 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 surroundinglands and destroying all vegetation.In 1766 the air was completely darkened fora distance of 150 miles, and in 1S45 a cloud of dust enveloped a vessel 200 milesto the south of the burning mountain. On that occasion ashes fell on the FiiroerIsles, and next day blackened the Orkney pastures.After every eruption the formof the mountain is modified, and after that of 1845 it was supposed to have lost200 feet in height. It has been frequently climbed since the first ascension byBank and Solander in 1770, and before the eruption of 1875 the main crest waspierced by two craters.The Xatla, or Kotlugja, southernmost of the Icelandic volcanoes, and 36 milessouth-east of Hekla, with which it has been often confounded, though now filledwith 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 disastrouswas 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 formedon the plain west of the Skaptar, and afterwards overflowed in two currentsbetween the hills barring its passage to the coast. Here were formed two oval