This section is from the book "Askja: Iceland's Largest Volcano", by W. G. Lock. Also available from Amazon: Askja: Iceland's Largest Volcano.
West of the new lava, a capital newly made road now crosses the barren moorlands and sandy wastes of the Orcefi for several miles, and over this we did not spare our ponies, a little over two hours' gallop bringing us to the lava-beds lying east of the Ndmafjall range of mountains bordering Myvatn. Here the made road came to an end, and we had to allow our ponies to slowly pick their way over the deeply fissured lava, the cracks and crannies in which are complete traps for tired out ponies, which do not pick their way so carefully as when fresh.
At the base of the Ndmafjall (Solfatara-mountain), we dismounted, and leaving our ponies in charge of Arni, H. and I started off to see the boiling mud wells in the solfatara at the base of the mountain. These boiling mud wells are the largest in Iceland, but as they have been more or less correctly described by at least half-a-dozen previous writers, I will only devote a few lines to their description. Between the Ndmafjall and the old lava beds to the eastward, resting upon a hot, white, viscid clay, is a plain of light coloured mineral earths, about half-a-mile in width from east to west by one and a-half in length from north to south. The earths, where wind and sun-dried, form a crust, in places capable of bearing a man, but there are large patches where it is unsafe to go, the crust being but an inch or so in thickness. The plain is studded with a number of low cone-shaped hillocks, from whose apices jets of steam ascend. These jets of steam mark where sulphur sublimation is taking place. The boiling mud wells lie on the eastern side of the plain, about half-amile from its northern end, in a bank of baked mud raised a few feet above the level of the plain, partly-surrounded by a pool of hot water. Prodding the treacherous ground with our whip-handles, that we might not inadvertently step on to a soft spot and break through into the scalding hot clay, we crossed to the mud wells. These numbered at the time of our visit twenty-seven, and were in groups in three crater-like basins in the mud bank, a short distance from each other. The basin which held the principal group was about twenty feet deep and seventy in diameter, and contained at this time seven wells, the largest about thirty feet in diameter, and the smallest about the size of an ordinary pitch-kettle. The boiling mud was as black as ink and of the consistency of porridge, and might with propriety, I think, be termed 'Hell Broth.' It was in a constant state of ebullition, large quantities of that in the largest well being every few minutes ejected with a roar to heights varying from six to eight feet. Similar 1 spouts' occurred from the largest well in each of the other groups. The wells in each basin are separated from one another by walls of dried mud: and I think it certain that the wells frequently vary considerably in size and number, the dividing mud walls within the basins constantly undergoing the process of destruction and re-construction, being at one time builded up by sediment ejected by the 'spouts' and at other times boiled away by the liquid heated matter, as during our visit, one of the walls separating two of the smaller wells toppled over, and the two became one.
Thus it is possible that one day there may not be more than one or two wells in a basin, while on another there may be a dozen, and if so, the difference in the number and dimensions of these ' Makka-luber' given by different writers is accounted for.
These boiling mud wells are a very interesting, though certainly not a beautiful phenomenon, and being situated at the junction of extensive lava-beds with a solfatara where hundreds of fumaroles are fizzing away, with a range of volcanic mountains, which also show signs of activity, within a few hundred yards to form a fitting background, they and their surroundings are very suggestive, as an American said of the Yellowstone region, ' of the Inferno very thinly crusted over.' 1 Umbra's ' lines heading this chapter, though not intended to do so, describe the scene to perfection.
Remounting our ponies a half-hour's ride through the pass in the mountain range, the Ndmaskarfi, brought us in sight of the famous Midge Lake. This sheet of water and its surroundings seen from the pass on a clear day, similar to what we were favoured with, is magnificent. Rounding a projecting spur of the mountain on the north side of the pass, the circumscribed view of an unusually gloomy defile, wherein not even a blade of grass clothes the acclivities, changes as if by magic to one over a wide expanse of lake, environed on the south and east with volcanoes, and studded with volcanic isles, miniature quiescent Strombolis whose weather-worn crater-cones rise from bases green with a prolific growth of angelica and grasses; their verdure presenting a pleasing contrast to the bristling lava-floods which fringe the lake. I have ridden through this pass a goodly number of times, but whenever I do so the sudden change always reminds me of the transformation scene of a pantomime, whose brightness and glories are invariably preceded and enhanced by a scene gloomy in the extreme. Myvatn is the second sized lake in Iceland, pmgvallavatn being the largest, and is said to have an area of thirty square miles, and to lie 900 feet above sea-level.
Professor Johnstrup says of the Myvatn district: ' There is no region in Iceland which has such a thoroughly volcanic character as the district east of Myvatn, in this respect it deserves the appellation classic; it is The Fire Focus of the North where hundreds of volcanoes stand silent witnesses of catastrophes respecting which history hath penned not a word It richly deserves the title given, ' Fire Focus of the North,' but I believe the true focus of volcanic activity in Iceland is Askja, and that the volcanic vents east of Myvatn are upon a channel running therefrom northward.
From the pass less than an hour's ride, first through a solfatara very similar to the one east of the range, and subsequently over an extensive bed of lava full of rifts and chasms, brought us to the door of Reykjahlifi, and in a very short time we were seated in the clean and very comfortable ' guest-room' before a dish of delicious boiled char, which during the preceding night had been disporting within the lava grottoes laved by the waters of Midge Lake.
 
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