1783. Eleventh eruption off Cape Reykjanes. In the same year occurred the most appalling eruption on record - that of Skapta. 1821. Third eruption of Eyjafjalla jökull. 1823. Katla. Twelfth eruption. 1845-46. Hekla. Twenty-sixth eruption. 1862. Trölladyngja erupted ash. There is much uncertainty about this explosion. From the above-given list it will be seen that the number of eruptions from Hekla, since 1004, inclusive, have been 26. Katla, since 894, inclusive, have been 13. There have been eighty-six eruptions, including outbreaks of lava, mentioned in some of the Icelandic histories, but the date of which it is impossible with accuracy to determine. These outbursts have taken place from twenty-seven different spots. Some of these vents have been active at several different periods, whilst others have erupted but once. The intervals between these explosions have been most irregular. Those of Hekla have varied from six to seventy-six years, and the intervals between the eruptions of Katla from six to three hundred and eleven years. At periods of peculiar activity more volcanoes than one have vomited simultaneously, as, for instance, in the year 1340, when the Orofa, Hekla, Mósfell, Herthubreith, and Trölladyngja erupted together; or, in 1510, when Hekla, Herthubreith, and Trölladyngja poured forth fire and molten rock at the same time. From 1724-30 was the period of greatest activity, twelve eruptions having taken place in those six years. The interval of greatest length between outbreaks of subterraneous fire was between the eruptions of Trölladyngja, in 1510, and Hekla, in 1554, a period of forty-four years. Between those of Hekla and Trölladyngja, in 1436 and 1475 respectively, thirty-nine years elapsed. Lava breaks forth not only from mountain sides, but from the grass-land under foot. The earth gapes and pours forth a flood of fire or casts up scoriæ, where meadows had previously existed. Such eruptions took place near Myvatn, in 1725, and at Thingvellir, in 1587. Lava and obsidian. Surturbrand. The traveller notices many instances of the lava having thus welled up and overflowed older strata. Beds of lava of this nature exist in the midst of the Storisandr, at Olfus, and throughout the Gullbringu sysla. Immediately after an eruption has taken place, the volcanoes of Iceland relapse into quiescence, and no smoke or steam rises from them, as it does from Vesuvius and Etna. The great majority have no circular craters; some have split themselves in the fury of explosion, and the lava has flowed from their sides, whilst the fire and water have found vent at the gashed crown. The perfectly symmetrical craters are Eldborg, Hverfjall, Vilíngafjall, Borg in Vithidal, and every mountain named Skál. The lava stream from Eireks jökull we distinctly traced to the mountain roots. It had not flowed from the summit, but from a chasm at the base. The Odatha Hraun is the most extensive lava bed, covering a space of 1,160 square miles. It has flowed from Trölladyngja and Herthubreith, and its recesses are quite unknown. It extends farther north than has been represented by Gunnlaugson, and reaches indeed as far as Burfell. The second largest bed is more broken and intercepted by hills and lakes. It extends from Skjaldbreith and Hlöthufell to Reykjanes, a distance of seventy-three miles. The tract around Hekla covers an area twenty-five miles long by ten broad. Obsidian has flowed from some of the volcanoes, as well as lava. The most important streams are near Krafla, Hekla, and at As, in Hvítárdalr. I found coarse obsidian Ók. on As already stated, the great mountain system of Iceland is formed of Palagonite tuff. The principal places where this rock has been pierced by trachyte are Baula, Thorishöfthi in Kaldidalr, a portion of Ók, and Laugarfjall, above Geysir. One of the most singular formations in Iceland is the surturbrand, a species of lignite, which lies in beds between clinkstone and trap. The wood is brightly glossed and black, free from all admixture of sulphur, very splintery in fracture. Logs and branches are preserved with their knots and roots; the circles denoting the age of the tree are very distinct at the ends of the fragments. In several places a layer of leaves overlies the coal in beds of four to six inches in thickness. The impression of the leaves, with all their delicate fibres, is perfect and very beautiful. The leaves belong to the poplar, willow, and birch. The alternation of basalt and surturbrand deserves peculiar attention from geologists, as the existence of leaves, and absence of marine shells in the deposit, seems to point out that there may have been a too hasty generalization, in concluding that all basalt is of submarine formation. Surturbrand is to be found in Borgarfjordar and Myra sysla. At Herathvatn, west of Northurá, is a bed two feet thick, black and lustrous. At Tandarasel there crops out a considerable amount, so also in the Hítárdalr. In the Barthastrandar, Dala, Isafjarthar and Strandar sysla, are three beds at different levels, extending through the whole peninsula at the heights respectively of 150 and 600 feet above the sea. At Lækir on the Barthastrand, at Forsdalr, in the Arnarfjord, they are found alternating with beds of leaves. Surturbrand has also been noticed at Svínadalr, Gnúpurfell, Barmahlith, Rauthasand, Stigahlith, Steingrims-fjord, &c. In Skagafjarthar, Eyjafjarthar, and Thingeyjar sysla it occurs; at Hofsgil in Gothdalr, Tinná in Skaga-fjord, Ulfa in Eyja-fjord, near Húsavik, the headland Tjörnes, between Skjalfunda and Axar fjords, in the Vapna-fjord, and at Thussahöfthajóta, near Eski-fjord. Few metals have hitherto been met with in Iceland. Copper Minerals. is found in some places, but in small quantities; plumbago has been discovered near Krafla. Magnetic iron is undoubtedly very widely dispersed through the volcanic rocks of the island; it occurs at Esja; and I found some near Eylifr, north-east of Myvatn. A vast and inexhaustible supply of sulphur is deposited by vapour jets in four spots-Hengill, near Thingvalla Lake, Krisuvik, Hlíthar-námar, and Fremri-námar, near Myvatn. None of this is now exported. The most remarkable boiling springs in Iceland are the Boiling Geysir at Haukadalr and at Reykir, Uxahver, the numerous springs. fountains of Reykholtsdalr, and those of Hveravellir. These by no means constitute all in the island, for there is hardly a valley without hot springs; and the natives have learned to distinguish their varieties by appropriate names. Hver is a general term expressing a warm or boiling spring; geysir is one which spouts; reykir, one which sends up clouds of steam; laug is a warm fountain which will serve as a bath; ölkelda is a mineral spring; and náma a pit of boiling mud. The characteristics of these fountains have changed within historic times. Tunguhver, which Sir George Mackenzie mentions as sending intermittent jets twelve or fourteen feet high, no longer alternates: it boils furiously, but its jets have been spoiled by travellers, who have choked its bore with stones. Hveravellir, spoken of by Olafsen and Povelsen as the most wondrous sight in Iceland, with its roaring mountain of steam, Lakes. Rivers. is now reduced to a dozen caldrons of boiling water. The geysir which Henderson saw in the crater of Krafla plays no longer; and its place is occupied by a still green pool of cold water. Some further instances will be adduced in the course of the narrative. Numerous lakes, either single or in groups, are scattered over the surface of the country. The largest are Thingvalla-, My-, and Hvítár-vötn; the principal groups are those of the Arnarvatn-heithi, and those at the foot of the Skapta, the remains of a considerable lake which existed previous to the great eruption of 1783. Myvatn was formerly considered the largest lake in the island, and so it may have been till it was nearly filled and dried up by the influx of lava from Krafla in 1724-1730. Thingvalla-vatn is now the most considerable sheet of water-it is ten miles long and between four and five miles wide. The contorted shape and irregularities of outline in Myvatn preclude one from giving any correct account of its dimensions. The Lagarfljót, in the east, is thirty miles long, but its width is only from half a mile to a mile and a quarter. On the Arnarvatnheithi, Gunnlaugson marks fifty-three lakes; but, from what I saw there, I am satisfied that not a fifth of those actually existing appear on the map, which, with regard to that district, is somewhat inaccurate. The rivers of Iceland are both numerous and large. The Jökulsá is the longest-it rises in the Vatna jökull, receives a tributary from Herthubreith, and, after a course of 125 miles, reaches the sea in the Axa-fjord, having passed exactly ten houses in its way, and having plunged into a chasm in a waterfall, the like of which is not to be seen in Europe. Other fine rivers are the Thjorsá, Skjálfandafljót, Hvítá, and Jökulsá á brú. A very curious phenomenon is the broad short river which is found in the south of Vatna jökull. In that portion of the island violent torrents, a couple of miles wide, and only eight or ten from their source to the sea, whirl down with frightful velocity, carrying with them masses of ice dislodged from the glaciers which are their feeders, and volumes of sand from the volcanic mountains which they drain. In passing Icelandic rivers, the traveller trusts either to his horse or to a ferry. The ponies swim well; but if the current be too strong there is considerable danger of their not being able to carry their rider across. Fords are continually shifting; and it is of the utmost importance for a stranger to secure a guide from a neighbouring farm, before venturing into the river. The beds are, in many cases, composed of quicksands, and the pebbly bottom on which the horses can find a sure footing changes with every spring. The fjords into which the rivers empty themselves may be Fjords. divided into two classes-the friths proper, and the bights or bays. The former are indentations in the line of coast, extending for a considerable distance into the land between precipitous mountains, whose tops are snow-covered, or continually veiled in mist, which the sea-breeze brings up with it. The noblest of these is the Isa-fjord in the north-western peninsula, fifty-two miles long, and winding between magnificent mountains, rising in inaccessible walls of basalt many thousand feet above the water's edge. Ten lesser friths open out of it, piercing the barrier crags, and stretching to the roots of the great barrelheaded jökulls of Dránga and Glámu. Other magnificent fjords are Hvamms, Skaga, Eyja, and Arnar fjords, all with distinct characteristics. The bays of Iceland are very extensive; the noble Faxafjord, sixty-five miles across, opens between capes Reykjanes and the silver sugarloaf of Snæfell. Breithi-fjord, studded with innumerable islets, the home of myriads of eider and wild duck, is forty-five miles wide; and Húnaflói, into which the Arctic sea rolls without a break, is forty-six miles long and twenty-seven wide. Other bights are the Axar, Skjálfanda, and Thistil fjords. A peculiar feature of Iceland is the gjá, pronounced gee-ow. Chasms. This is a fissure in the crust of the earth, formed by earthquakes, or volcanic upheavals and sinkings of the land. These zig-zag rents run from north-east to south-west. The most remarkable are the Allmanna and Hrafna gjás, at Thingvellir, the huge chasm in Katla, the rift into which pours the Jökulsá at Dettifoss, and the Stapa, Hauksvörthu, and Hrafna gjás, in Gullbryngu sysla. The first-mentioned extends for four miles, and is, in one spot, a hundred and thirty feet deep. The Hrafna gjá, or Raven rift, is somewhat longer, but only fifty feet deep. In 1728 there opened a chasm in the Orofa of immeasurable depth. The Archdeacon Jón Thorlaksson, who visited it, found a large stone at one spot crossing the lip of the gulf. He and a companion dislodged it, and sent it down into the abyss, but, though they listened attentively, they could not hear it reach the bottom. The great fissure of Katla has never been properly examined. It runs south-west to north-east, then turns at a right angle from south-east to north-west. This is probably the crater of the volcano. The only person who has been near the chasm is an Icelandic priest, Jón Austman, who ascended the mountain in 1823. He describes it as quite inaccessible, all |