Oct. 3, 1878] 



NATURE 



597 



of the eruption, in company with three friends. Two guides 

 accompanied us, and we took a relay of ponies in case of 

 accident or fatigue. We left the Galtaloekr farm (see 

 the map, route a a) at 7.30 A.M., crossed a small stream- 

 let, and soon came upon a growth of dwarf birch-trees 

 from one to two feet in height. Here we put up a covey 

 of very tame ptarmigan. On emerging from the under- 

 wood we entered a long level plain of volcanic sand and 

 ash, extending between the river Thiorsa and the smaller 

 stream called Vestri-R^gd. We cantered over the plain 

 for about ten miles, turning aside for a moment to look 

 at the falls of the Thiorsa, at the southern base of 

 Burfell. The substance of the plain is black volcanic 

 sand and ash, with occasional white, grey, and red 

 patches of pumice. At 9.15 A.M. we found ourselves 

 near the termination of the Vestri-Rdng^, and, bearing 

 to the south-east, we forded the stream, and almost im- 

 mediately afterwards came upon fields of volcanic ash 

 and lava. The ground now became very rough, masses 



of lava were strewn in all directions, and there was of 

 course no track. We passed several cones of ashes 

 emitted by extinct craters, and presently saw in front of 

 us Raudaskal — the red mountain — a subsidiary cone pro- 

 bably thrown up in 1554. We wound along the Rau- 

 daskal valley, which is between six and seven miles in 

 length and nearly two miles broad, passing by the base 

 of several large cinder-cones. The new lava of 1878 

 was soon sighted, and we picked our way for about three 

 miles between the edge of the field and the sloping sides 

 of the cinder cones. By the time we had ridden some 

 twenty-three miles from Galtaloekr we found ourselves at 

 the edge of a field of old lava, contiguous to the lava of 

 1878, and in sight of the largest of the new craters. The 

 summit of Hekla was on our right, about four miles 

 distant, and Krakatinkr was nearly facing us to the south. 

 H ere we left the ponies, tied head and tail together, to prevent 

 straying during our absence. The only possible way to get 

 nearer to the new crater was to clamber over the old 



Map o£ Mount Hekla showing position of the new craters. Route a a, from Galtaloekr to the new craters. Route h b, from Galtaloekr to the sumccu 

 Hekla. The dotted line between Valaknukr and Krakatinkr shows the position and extent of the lava field of 1878. 



Scale 



\ i 



— Miles Danish. 



bed of lava, which, although very rough and jagged, 

 was not difficult to cross, on account of its covering of 

 moss. At the edge of this bed we came upon a small 

 tract of old snow, covered with volcanic ash to the 

 depth of about eight inches. Then we reached the new 

 lava and saw the largest cone of the new craters imme- 

 diately in front of us, and about half-a-mile distant. 

 The new lava was more rough and cindery, at least at 

 the surface, than any I have ever seen around Etna or 

 Vesuvius. Its surface was extremely jagged, and it 

 was broken into ridges, and crests, and sharp pinnacles, 

 which yielded uncertain support to the foot or hand. 

 Hence it was both difficult and dangerous to cross, and 

 we could only climb over a few dozen yards of it. 

 Standing upon its surface we could see the cone of the 

 largest of the new craters emitting small quantities of 

 vapotir and incrusted with red and yellow substances. 

 The lava field extended both to our right and left, and in 

 .some places it was giving off vapour. The edge of the 



field along which we travelled was about twenty feet in 

 depth, but in some places it was piled to a much greater 

 height. The lava was very close and compact some 

 distance from the exterior; it was cracked and split in 

 all directions. White incrustations of salt {not chloride 

 of ammonium, which is common in some lavas) were 

 often noticed at the points of fracture ; also brilliant red 

 and yellow incrustations, which are often mistaken for 

 sulphur, but which in the case of this lava, at least, I 

 have proved to be sesquichloride of iron. In some parts of 

 the lava these incrustations covered many square yards, 

 while fumes of hydrochloric acid were freely emitted in 

 their vicinity. The sesquichloride when removed from the 

 lava rapidly absorbed moisture from the air and formed 

 an intensely acid solution. We left the neighbourhood 

 of the new crater at 2.30 P.M., rested at 4 p.m. on the 

 banks of the Vestri-Rdngd, and reached Galtaloekr at 

 6. 1 5 P.M., having left it eleven hours before, and travelled 

 over nearly fifty miles of volcanic coimtry. 



