Lang Jökull is an immense waste of snow-covered mountain, extending about forty-three miles from north-east to south-west, of breadth varying between eight and twelve miles. The mass rises into points of greater elevation along the edge than, apparently, towards the centre; and these mountains go by the names of Ball Jökull, Geitlands Jökull, Skjaldbreid Jökull, Blàfell Jökull, and Hrutafell. Skjaldbreid Jökull is opposite the volcanic dome of Skjaldbreid, an extinct volcano, with its base steeped in a sea of lava. Due east of Geitlands Jökull is another glacier-crowned dome, called Ok, from which it is cut off by a trench of desolate ruined rock filled with the rubbish brought down by the avalanches on either side--a rift between black walls of trap, crowned with green precipices of ice, which are constantly sliding over the rocky edges and falling with a crash into the valley: this valley is called Kaldidalr, or the cold dale--a title it well deserves. Those who traverse it from the south encamp at a little patch of turf around some springs, at the foot of Skjaldbreid, Brunnir by name, and thence have twelve hours’ hard riding before they see grass again on the Hvitá, north of Ok. Half-way through this Allée Blanche is a mountain of trachyte, which has been protruded through the trap, from which it is clearly distinguishable by its silvery gray and ruddy streaked precipices, so different in colour from the purple-black of the trap. This mountain is called Thorir’s Head, and is popularly supposed to mask the dale discovered by Grettir. The elaborate map of Iceland published by Gunnlaugson indicates the valley as winding from opposite Skjaldbreid to this point, but this is conjectural; and it will be seen by the sequel that it is inaccurate. North of Geitlands Jökull is an extraordinary dish-cover-shaped cake of ice raised on precipitous sides, called Eîrek’s Jökull, a magnificent, but peculiar pile of basalt, ice, and snow. Before proceeding with the narrative of Messrs. Olafsen and Povelsen, and of the two clergymen, we may observe that several circumstances tend to give a colour of probability to the account in the _Gretla_.