extremely brittle was the texture of the lava, even last autumn, when so far cooled as to suffer any one to

Solidity of the lava.

hold it in his hand, that the application of moderate pressure instantly reduced it to a fine powder; but it was now on the contrary become considerably solid, insomuch that it was with great difficulty I could work through it, in many places, with the boringinstrument. Notwithstanding this, it was still very dangerous and unsafe, and was every where difficult to walk over. Unsafe it must also of necessity remain for a long time, on account of the numerous sharp points and projections with which its surface is covered, and upon which it is scarcely possible to tread with the thin Icelandic shoes, made of raw hides, or even with thick and properly soled ones, without immediately cutting them through. Much danger, too, arose from the circumstance of the hot vapors which it concealed, having, previously to the lava becoming thoroughly cool, produced, as above mentioned, innumerable hollow places, the arch-way or ceiling of which, that inserted in Dr. Crell's Annals of Chemistry, for 1784. Book 11. p. 323.

though in appearance resembling the rest of of the lava, yet was not sufficiently thick or strong to bear the human weight.

That the floors or bottoms of these cavities owe their colored appearance to the different kinds of sulphur, iron, and other metallic substances which have melted and dropped from the arched surface, will readily be perceived, without the necessity of my remarking it; and it will likewise easily be understood, that the spiculæ, which hang from the ceilings, are nothing more than a part of the lava, more or less intermixed with strong substances, which, whilst dropping, had cooled and become indurated.

It has already

§. XXVIII.

been mentioned, (§ xvii.) that the great heat arising Attempts with the boring-instruments. from the lava was no small obstruction to the experiments we had hoped to have made with our boring-instruments, in the hilly country, as well as in the vallies; insomuch, that I began to entertain fears lest this circumstance should render these

instruments quite useless; preventing us, as

.

it did, from employing them, except where the ground was proportionably cool. It is scarcely in the power of any one to form an idea of the difficulty that attended this part of our labors. To be continually turning the instruments round, and working through the hot, hard, and uneven lava, while we were at the same time treading upon its sharp-pointed edges, was certainly a task as painful as it was irksome. Nevertheless, by these trials, I found that the lava in some places did not lie more than six or eight feet deep; that in many it did not exceed ten feet; and that wheresoever, as was the case in certain situations, it was far deeper, its depth seemed wholly to depend on the peculiar nature of the country. Both below the lava, and close by its side, was found either sand or earth of the same kind as that which appears every where in this district, at a distance from the fire, as in the peat-bogs or in the grounds where the sea-lyme grass (Elymus arenarius) grows; but no kind of slate could be discovered in the neighborhood. The boringinstruments were useful, in enabling me to ascertain the quality of the soil below and

about the lava, as well as the depth and nature of this latter beneath the surface of the ground, and they farther confirmed me in the opinion which I have stated above, that the volcano was to be considered as arising from a partial eruption, and not from any internal and universal ignition of

the earth.

Height of the

The height, to which the lava. heaps of lava rise in the level country, is in some parts very considerable; particularly at Skalarfiall, where they have reached up to the rocks that project from the south side of the mountain: yet, nevertheless, were we to calculate its extreme height on the plains at an hundred feet (and even this is not quite a fourth part of what has been stated *), I am still persuaded we should greatly exceed the reality.

§ XXIX.

It has been already noticed in its proper place, that, after the first breaking out of

* See Holme's Account of the Fire, p. 19, where the height of the lava is estimated at seventy fathoms, or four hundred and twenty feet.

State of the weather after the 1st of June, 1783.

the fire, a great quantity of ashes, sand, and sulphureous

dust was thrown over the adjacent districts, particularly those of Siden and Fliotshverfet. The long continuance of westerly winds, too, drove the sand-bank away from Skaptartungen to the places just named; and the vast quantity of burning sand falling around scorched up all the grass in the fields about Fliotshverfet to such a degree, that there were no means of support for the cattle, and the inhabitants fled from all the farms in this district, excepting the most easterly one, called Nupstad, which, together with the neighboring farm of Raudaberg, remained uninjured by the hot ashes. It is an undoubted certainty, that, if Providence should be pleased to grant better seasons to Iceland than the present, not only the parsonage of Kalfafell, with the cottage of *Kalfafellskot, appertaining to it, but also the farm-houses of Nupar, Mariubacki, and Hvoll, will, in a very few years, be restored to their former condition; especially as the lava itself has not reached them. We may then reckon the number of farm-houses damaged at twenty-five, instead of twenty-nine (see