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forming perpendicular cliffs of great height. These were rapidly 

 falling in and had formed in several places steep slopes of pumice and 

 debris, which it was quite possible to descend. All access to the 

 floor of the crater, however, was prevented by an interior rim 

 of precipice immediately at the base of these heights. Three 

 separate lines of fissures, pits and irregular openings, diverged 

 from the centre of the crater to the south, north-east, and 

 north-west respectively, and, when he was there, still con- 

 tinued to erupt vast volumes of steam, a dark granulated fatty 

 earth, and a little water. It was from this volcano that all the pumice 

 was ejected which had fallen in a band of ever-extending radii east- 

 ward from the volcano to the sea-shore, destroying six farms in its 

 course, and injuring others. Considerable streams of water had 

 evidently flowed from this crater, and this was the more remarkable, 

 as it was neither a glacial nor a snow-capped mountain. This water 

 was probably derived from the melting snows of the Vatna Jokull 

 which had found its way through the loose and cavernous ground 

 (principally sand and lava) to the chimney of the volcano, where it had 

 accumulated. The fissure in the Myvatos oroefl, which he had before 

 mentioned, opened slightly before the eruption of Oskja-gii ; from it 

 had flowed a lava: stream about 13 miles in length, and varying from 

 one to three in breadth. The various eruptions from this fissure had 

 cast up six or seven subconical mounds, one of which he saw in violent 

 eruption last year ; it was then about j soft, in height. The ground in 

 the immediate neighbourhood of this crevass was greatly fissured and 

 dislocated, and an extensive subsidence had taken place around its 

 southern extremity. 



Time would not allow him to dwell any longer upon the volcanoes 

 of Iceland, and he would only remark that their general characteristic 

 was lack of height when compared with the volcanoes of other 

 countries, and their irregular occurrence. First they broke forth amid 

 the snows of lofty JokuUs, then from beneath mountains that for ages 

 had stifled volcanic energy, then in the midst of plains already 

 desolated by prehistoric eruptions. This eccentric shifting of volcanic 

 foci was most probably the result of the numerous fissures and cracks 

 in the superficial rocks of Iceland that had been formed by the 

 various earthquakes which from time to time had shaken the island 

 to its very foundations. 



He would now briefly consider the products of these volcanoes, 



