INTRODUCTION. phical and ICELAND lies just south of the Arctic circle, touching it in the Geogra north. It is situated between lat. 63° 25′ and 66° 30′ north, physical and long. 13° 38′ and 24° 40′ west. The shape is peculiar. It is that of an irregular ellipse, with a considerable excrescence in the north-west, which is united to the mainland by a neck only 4 miles across at the narrowest part. The island is one-fifth larger than Ireland, and contains about 37,000 square miles. Its greatest length is 308 English miles, and greatest breadth 190. It is deeply indented with fjords on all sides except the south. It owes its upheaval entirely to volcanic agency, and is composed exclusively of igneous rocks. The interior of the island consists of an elevated band of Palagonite tuff, pierced by trachyte veins; on either side of this formation is basalt. It has been generally held that the island was traversed by a broad trachytic valley, hemmed in between chains of trap mountains; but this view is erroneous. Instead of a vale, we have the great jökulls of the centre formed of tufa, and only the fells and smaller ice-mountains on the north coast composed of basalt. The mountain system is in the south, and takes the shape of a triangle, having for base a line drawn from Ók to Eyjafjalla, and for apex, Thrándar jökull, which towers above the Beru-fjord. A glance at the map would convey the idea that extensive plains occupied the area of the lower portion of this triangle, but such is not the case. The space intervening between Blá-fell, Hekla, Torfa jökull, and the vast ice regions of Hofs and Vatna jökulls is, in fact, occupied by ground rising gradually in rolling "heithi” sweeps, till it meets the snows of Skapta. Towards the apex of the triangle, the glacier mountains form a compact mass called Vatna, or Klofa jökull, covering an area of 3,500 square miles of unexplored snow recesses. North of this triangular mountain system is a triangular elevated plain, with the features. Mountains. Volcanoes. base towards the east, extending from Thrándar jökull to Langanes, and with its apex at Baula. This plain is a complete desert, covered with vast lava beds, as the Odatha Hraun, with extensive tracts of black sand, as the Stori and Sprengisandur, or with rock and mud sprinkled with lichen and moss in sheltered hollows, as the Arnarvatn Heithi. This wilderness is traversed by three main routes, the Thvídœgravegr, the Kjalvegr, and the Sprengisandur way. These two triangles form a parallelogram including 20,000 square miles of country perfectly barren and uninhabitable, and only partially explored. It has been estimated that but 4,000 square miles of Iceland are inhabited; the rest of the country is a chaos of ice, desert, and volcanoes. The mountains of Iceland are divided into two classes, the fells and the jökulls. The former are, for the most part, free from snow during the hottest portion of the summer; but the latter are shrouded in eternal ice. The conformation of the mountains is very varied. The jökulls have generally rounded heads of ice resting on abrupt flanks of rock. This ice is formed by the pressure of enormous superincumbent masses of fresh snow, converting this at any depth to blue glacier ice. Sections such as may be seen in Kaldidalr and on the flanks of Eireks jökull give to these beds a thickness of about one hundred feet. As there is a constant thrust from the highest points of the mountain exerted upon the ice, it moves slowly over the rocky ledges, and breaks off in crags of green ice, which fall to the bottom of the precipices with a roll like thunder. On the south of the Vatna and Myrdals jökulls, where the mountains shelve gently to the sea, glaciers resembling those of Switzerland may be seen, but they are entirely absent from the centre of the island. The principal jökulls are--the Orofa, height 6,241 feet; Eastern Snæfell, 5,160 feet; Eyjafjalla, 5,432 feet; Herthubreith, 5,290 feet; and Western Snæfell, 4,577 feet. The latter has alone been surmounted. Mr. Holland, in 1861, ascended to a great height on the Orofa, but did not gain the summit. The fells are mountains of different character; they may be rounded at top, but they support no ice-fields, and are inferior in elevation to the jökulls. In shape they vary considerably some are saddlebacked, others conical or pyramidal. Some, as well as the jökulls, are volcanoes, and have often caused much havoc. Hekla, for instance, is a fell, whilst the terrible Skapta is a jökull. The most violent volcanic action seems to lie in a band from Krafla to Reykjanes. In this belt lie the following principal volcanoes-Krafla and Leirhuukr, both near Myvatn; Trölladyngja, in the Odathahraun; Skapta and Orofa, the westernmost points of the enormous Vatna jökull, Katla or Kötlugjá, and its twin mountain Myrdals jökull, and Hekla. The total number of recorded eruptions is :- 894. Katla erupted for the first time. 934. Katla for the second time. 1000. Katla again (the date is not certain). 1004. Hekla for the first time. 1029. Hekla for the second time. 1104-5. Hekla for the third time. 1113. Hekla for the fourth time. 1188. Second eruption of Trölladyngia. 1204. Hekla. Sixth eruption. 1210. At sea, near Reykjanes. 1219. At sea, near Snæfells jökull. 1222. Hekla. Seventh eruption. 1222-26. At sea, off Reykjanes. Four outbreaks. 1237. Seventh eruption at sea. 1240. Eighth eruption, off Reykjanes. 1245. Myrdals jökull, south-west flank, called Sólheimar jökull. 1262. Sólheimar jökull again. 1294. Hekla. Eighth eruption. 1300. Hekla. Ninth eruption, and one of the most violent. 1311. Rauthukambar, in Austur Skaptarfells sysla. 1311 or 1332. Katla. Fourth eruption. 1332. Eruption of the Oræfa jökull. 1340. Second eruption of the Orofa; and, in same year, the tenth of Hekla; also, the only known eruption of Mósfell, in Kjósarsysla. Herthubreith also vomited; so also Trölladyngja. 1359. Fourth eruption of Trölladyngja. 1362. Eruption of the eastern portion of the Orœfa; and the third of the western head. 1374. Hekla. Eleventh eruption. 1390. Hekla. Twelfth eruption. 1416. Katla. Fifth eruption. 1422. Ninth eruption in the sea, off Reykjanes, 1436. Hekla. Thirteenth eruption. 1475. Trölladyngja. Fifth eruption. 1510. Hekla. Fourteenth eruption; at the same time the second eruption of Herthubreith, and the sixth of Trölladyngja. 1554. Hekla. Fifteenth eruption, from a side crater. 1580. Sixth eruption of Katla, which then formed the huge rift between itself and Myrdals jökull. The volcano has since been called Kötlugjá. 1583. Tenth eruption in the sea off Reykjanes; and the sixteenth of Hekla. 1587. Bursting of ground near Thingvalla lake; clouds of smoke and streams of lava gushed forth. 1597. Seventeenth eruption of Hekla. 1612. Eruption of Eyjafjalla jökull. 1619. Eighteenth eruption of Hekla. 1625. Seventh eruption of Katla. In the same year, the nineteenth of Hekla. 1636. Hekla. Twentieth eruption. 1660. Kátla. Eighth eruption. 1693. Hekla. Twenty-first eruption. 1716. Eruption of ash and smoke from Ball jökull. 1717. Eyjafjalla jökull. Second eruption. 1720. Fourth eruption of the Orœfa. 1721. Ninth eruption of Katla. 1724-30. Eruption of Krafla, near Myvatn. 1725. Eruption of lava in a grass-grown plain at Hítaholl, near Myvatn; followed by a similar outburst in the grass-land of Bjarnaflag. In the same year, an eruption of Leirhnukr; and also of Skeitharár jökull, west of the Orofa. That of Leirhnukr lasted till 1729. 1727. Second eruption of Skeitharár jökull, and the fifth from Oræfa jökull. 1727-28. Tenth eruption of Katla. 1728. Second eruption in the grass-land at Bjarnaflag, and, in the same year, a slight outburst from Hekla. Another eruption of lava took place in Horsadalr, near Myvatn, and filled the valley; at the same time, the earth opened near Reykjahlith and threw up ash, fire, and lava. Sithu jökull, in the south, also erupted. 1748-52. The Hverfjall was thrown up. 1754. Hekla. Twenty-third eruption. 1755. Eleventh eruption of Katla. 1766. Four-and-twentieth eruption of Hekla. |