This Arctic Phlegethon is mottled with pits of boiling bolus. There are four principal groups of these mud cauldrons, each in a basin of baked mud, elevated a few feet above the level of the plain. In 1910 one of these groups contained seven cauldrons, the largest being thirty feet in diameter. The cauldrons are not permanent but crust over from time to time and new ones form in the adjacent areas. The mud rises slowly in a gigantic bubble, like the sticky bubbles on the surface of hot molasses candy, until the gas pressure is sufficient to burst the film, when a cloud of gases suddenly shoots upward, a hot shower of mud is ejected and then the entire mass slides back into the bowels of the earth with a horrid, sickening gasp. It is now safe to mount the rim and watch the mass as it slowly wells upwards for another display. Standing in a bath of vapors one looks backward over the track whence he came and notes tiny columns of steam marking the trail along which he so recently advanced. Every place in the crust that was punctured with the staff is slowly changing into a cauldron like the one at his feet and the traveller experiences a sensation of uneasiness, knowing, as he does, that in a brief time a new line of cauldrons will be in operation and for the first time he fully realizes the insecurity of his position and he longs for the solidity of the lava ridge where he left the hobbled ponies. Because it suggests the food that may be provided for the guests of the Inferno, the Icelander has named the material within the smoking cauldrons “hell-broth” and the name can not be improved. They boil and splutter, spatter and emit abundant volumes of steam and make a great fuss over the little matter of a solid nature that is ejected. These spiteful explosions are worthy of greater results. “And still the smouldering flame lurks underground And tosses boiling fountains to the sky.” For two hours we wandered among the fumaroles and fountains of seething mud. Oftentimes the crust cracked viciously beneath our feet and we retreated precipitously to a thicker portion of the shell which covers this vast subterranean fire. It gave us much amusement to plug up the orifices of the small fumaroles with plastic clay and sulfur and to wait for them to burst forth spitefully and hurl out a shower of scorching mud.