At 5 A.M. the next morning we were on horseback, and away over the sand and the lava of Mývatns Örœfí, leaving the Vatna Jökull and the land of the outlaws behind us, enveloped in clouds of light grey dust which were blown up from the pumice by a S.E. wind. This dust, I must explain, was of the most irritating nature, resembling finely-powdered glass; our clothes got saturated with it, and I was already beginning to feel its effect in the severe abrasion of skin it was inflicting upon me. By 12 A.M. we were level with Grímstaðir, only much more to the west, and here we stopped to allow the horses to graze off the wild oats, for the heat of the sun was intense. After lunch we must all have taken a nap, for suddenly looking up, I found it was one o’clock, and the horses were nowhere in sight, and more than an hour elapsed before we recovered them. Having secured the vagrant animals, we made for the new lava, which was produced by the eruptions of last spring in the Mývatns Örœfí. Sulphurous and acid vapours had long announced its proximity, although the wind was unfavourable for their reaching so far. This lava stream, which is about fifteen miles long, and varies from one to three broad, has flowed almost entirely over ancient lava streams, most of which have flowed from an old crater situated in the vicinity, called Sveinagjá. The new lava extended to about an English mile to the north of the old road from Reykjahlíð to Grímstaðir.
At this particular point it is bordered by a rather fertile stretch of ground, where a few sheep managed to sustain a miserable existence on cinders and salix, though further to the north and east there are excellent pastures. The lava stream was basaltic, and presented the usual chaos of black crags, waves, and fanciful shapes, blisters, and heaps of clinker. It was intensely black, and still hot; thin, pungent choking fumes being emitted in all directions, while from various places puffs of steam were constantly bursting out. This stream, or rather, these two streams, which have since joined one another, I find have flowed from a long fissure in the plain, the course of which was marked by a line of conical mounds thrown up by the eruptions in the late spring; of these a fuller description will be found upon another page, and an account of the previous eruption in the Appendix.