entirely over-ran the farms Eystradal and, Thverardal. All the adjoining houses and the greater part of the enclosures were buried under the lava, so that the places where the buildings formerly stood are no longer visible. These latter eruptions, also, have done much damage to the farms Selialand and Thvera, and the inhabitants were entirely frightened away from the parish of Halfafells, although no houses were destroyed in these places.

The eastern fire-stream broke out at a much later period than the western one, and continued raging much longer, frequently at intervals bursting through the crust or surface, which had become indurated. It is even asserted that in February, 1784, a fresh eruption proceeded from the mountain, and caused the lava, in the eastern branch, to rise to such a considerable height as it

now is.

§ XV.

So much for the progress of the fire, and the immediate destruction occasioned by it. Were I here to relate all the contradictory,

insignificant, ridiculous, and superstitious accounts that are reported of the eruptions, it would be both an useless and a tedious task, especially since the greater number of such accounts are the offspring of fear and ignorance. But two questions naturally present themselves to our minds, which are too closely connected with the subject to allow me to pass them over in silence.-The first is, "whether the subterraneous Respecting the nature of the fire. fire is to be deemed only an

eruption, or the earth itself is to be considered as ignited; or whether these two causes may not have operated together?" I am well aware that the greater part of those persons that were on the spot bring forward various arguments in order to prove that the earth itself was ignited, but the reasons they assign appear to me to be weak and in themselves highly contradictory. It is remarked, that before the liquid lava had over-run several of the places now burnt, fire had actually, here and there, broken through the soil. We are informed that the proprietor of the farm Botnar, in Medalland, had, on the first breaking out of the fire, collected eighty sheep and placed them, as

he supposed, in a state of security upon a small island, but that, before the farmer had returned to his own house, the fire appeared to break out from that very island, and he had the misfortune to be the sad spectator of the ruin of himself and family. This account, indeed, was, as far as I was able to ascertain, perfectly correct, but nevertheless it does not at all prove that the accident was caused rather by the earth itself being on fire than by a fire-stream: for, at the very moment that the farmer had collected his sheep upon this spot, the lava was rushing along with the greatest imaginable rapidity, and took quite a different course from that which was at first expected; proceeding towards a neighboring river and along its channel, till it arrived at the island, which it burned together with the sheep.

The Icelandic annals relate a long series of such eruptions, continued through whole centuries; but we do not find any account distinctly describing the nature of the lavastreams which formerly over-ran whole districts. The damage sustained is simply

noticed, but upon the subject of the progress of the fire, authors are entirely silent. It is therefore quite natural that the late fire should appear particularly frightful to the spectators, and that they should be led to suppose that the fire broke forth from the entire and uninjured crust of the earth, at considerable distances from the fire-stream itself. My own opinion is that such appearances always exist when the stream of lava, for the first time, pours down from the mountains upon a fertile tract of land, or upon a soil that is loose and free from obstructions. We may readily imagine what an immense weight must fall upon the earth, when the lava rushes down from the high to the low lands, and we may in like manner conceive it possible for the lava to burn and force itself a passage to a considerable depth below the surface of the earth. The lava itself being a fluid, driven forward by every new accession of matter, it can, without doubt, proceed in its course as well below as above the surface of the ground, and even in some instances with greater rapidity. Above it must work its way over all inequalities, and where the stream of lava has

to cross a valley in its course, its progress is necessarily impeded till the hollow is filled up: it must, too, carry with it a great number of stones and other things, with which such streams of lava are filled. Beneath the surface, on the contrary, where only that lava can penetrate which is in its purest and most fluid state, it finds its way into many places through a more loose and open soil, percolating like water, continuing the same even course, and is not stopped by the above-mentioned inequalities; but flows forward uninterruptedly to a great distance. The fire having in this manner forced its way down into the earth, and proceeded forward, it is easy to conceive that, in consequence of the vast heat arising from so much burning matter, the damp and moisture would be converted into vapors, and that these, by the force of the lava, would be driven up through the crevices, to the surface of the earth, appearing above ground in flames. Where, indeed, the soil is full of rocks, it is not possible for the firestream to proceed with any velocity beneath the surface, much less through the old lavatracts, which are of considerable depth.