78 THE POLAR WORLD. 



course is frequently very short, particularly along the southern coast, where 

 the jokuls from which they derive their birth are only sei^arated from the 

 sea by a narrow foreland. In their impetuous flow, they not seldom bear huge 

 blocks of stone along with them, and cut off all communication between the 

 inhabitants of their opposite banks. 



The chief rivers of Iceland are, in the south, the Thiorsa and the Ilvita, 

 which are not inferior in width to the Rhine in the middle part of its course ; 

 in the north, the Skjalfandafljot and the Jokulsa and the Jokulsa i Axarfirdi, 

 large and rapid streams above a hundred miles long ; and in the east the La- 

 garfliot. As may be exj^ected in a mountainous country, containing many 

 glacier-fed rivers, Iceland has numerous cascades, many of them rivalling or 

 surpassing in beauty the far-famed falls of Switzerland. 



One of the most celebrated of these gems of nature is the Goda-foss, in the 

 northern part of the island, formed by the deep and rapid Skjalfandafljot, as it 

 rushes with a deafening roar over rocks fifty feet high into the caldron below ; 

 but it is far surpassed in magnificence by the Dettifoss, a fall of the Jukulsa i 

 Axarfirdi. 



" In some of old earth's convulsions," says its discoverer, Mr. Gould, — for 

 from its remote situation, deep in the northern wilds of Iceland, it had escaped 

 the curious eye of previous travellers — "the crust of rock has been rent, and a 

 frightful fissure formed in the basalt, about 200 feet deep, wuth the sides co- 

 lumnar and perpendicular. The gash terminates abruptly at an acute angle, 

 and at this spot the great river rolls in. The wreaths of water sweeping 

 down ; the frenzy of the confined streams where they meet, shooting into each 

 other fi-oni either side at the apex of an angle ; the Avild rebound when they 

 strike a head of rock, lurching out half way down ; the fitful gleam of battling 

 torrents, obtained through a veil of eddying vapor ; the Geysir-spouts which 

 blow up about seventy feet from holes v>^henc6 basaltic columns have been shot 

 by the force of the descending water ; the blasts of spray which rush upward 

 and burst into fierce showers on the brink, feeding rills which plunge over the 

 edge as soon as they are born ; the white writhing vortex below, with now and 

 then an ice-green wave tearing through the ioam to lash against the walls ; the 

 thunder and bellowing of the water, which make the rock shudder under foot, 

 are all stamped on ray mind with a vividness which it will take years to efface. 

 The Almannagja is nothing to this chasm, and Schaffhausen is dwarfed by 

 Dettifoss." 



The ocean-currents which wash the coasts of Iceland from opposite direc- 

 tions have a considerable influence on its climate. The south and west coasts, 

 fronting the Atlantic, and exposed to the Gulf Stream, remain ice-free even in 

 winter, and enjoy a comparatively mild temperature, while the cold Polar cur- 

 rent, flowing in a south-western direction from Spitzbergen to Jan Mayen and 

 Iceland, conveys almost every year to the eastern and northern shores of the 

 island large masses of drift-ice, which sometimes do not disappear before July 

 or even August. According to Dr. Thorstensen, the mean annual temperature 

 of the air at Reykjavik is +40°, and that of the sea +42°, while according to 

 Herr von Scheele the mean annual temperature at Akureyre, on the north coast, 



