30 



ISLANDS OF THE NORTH ATLANTIC. 



reservoirs, which steadily increased in volume for six months without being able 

 to reach the sea. The larger of these was 50 miles long, with a mean breadth of 

 15 miles, and both were 500 feet deep in many places. The amount of lava dis- 

 charged on this occasion was set down at 654 billions of cubic yards, a quantity suffi- 

 cient to cover the whole globe with a layer nearly a twenty-sixth part of an inch in 

 thickness. The finest pastures in the island were buried in ashes, the flocks perished 

 in thousands, and then came famine and pestilence, in two years destroying 9,33G 

 human beings, 28,000 horses, 11,500 head of cattle, and over 190,000 sheep. 



Beneath the vast Klofli or Yatna snow-field unknown volcanoes are active, 

 at times diffusing sulphurous or pestiferous vapours over the whole island. In 



Fig. 12. — Quicksands of the Skaptar-Jokull. 

 Scale 1 : 1,000,000. 



17° WoFGr. 



18G1 these sub-glacial fires, possibly accompanied by streams of surface lava, 

 melted such a quantity of snow that the southern plains were entirely flooded, and 

 80 miles from the shore some English vessels had to make their way through 

 a current of muddy water 30 miles wide. Since then the hydrography of this 

 region has been completely modified. The river Skei^ara, formerly flowing from 

 the east side of the glacier of like name, has been replaced by insignificant rivulets, 

 while the true Skei^ara, in certain seasons almost impassable and several hundred 

 yards broad, now flows 8 miles to the west of its old bed. 



