50 LETTERS FROM HIGH LATITUDES. [VII. 



Judge then of my astonishment when, a few minutes after- 

 wards, I was arrested in full career by a tremendous precipice, 

 or rather chasm, which suddenly gaped beneath my feet, and 

 completely separated the barren plateau we had been so pain- 

 fully traversing from a lovely, gay, sunlit flat, ten miles broad, 

 that lay — sunk at a level lower by a hundred feet — between 

 us and the opposite mountains. I was never so completely 

 taken by surprise ; Sigurdr's purposely vague description of 

 our halting-place was accounted for. 



We had reached the famous Almanna Gja. Like a black 

 rampart in the distance, the corresponding chasm of the 

 Hrafna Gja cut across the lower slope of the distant hills, 

 and between them now slept in beauty and sunshine the 

 broad verdant 1 plain of Thingvalla. 



Ages ago, — who shall say how long? — some vast commo- 

 tion shook the foundations of the island, and bubbling up 

 from sources far away amid the inland hills, a fiery deluge 

 must have rushed down between their ridges, until, escaping 

 from the narrower gorges, it found space to spread itself into 

 one broad sheet of molten stone over an entire district of coun- 

 try, reducing its varied surface to one vast blackened level. 



One of two things then occurred : either the vitrified mass 

 contracting as it cooled, — the centre area of fifty square miles 

 burst asunder at either side from the adjoining plateau, and 

 sinking down to its present level, left the two parallel Gjas, 

 or chasms, which form its lateral boundaries, to mark the 

 limits of the disruption ; or else, while the pith or marrow of 

 the lava was still in a fluid state, its upper surface became 

 solid, and formed a roof beneath which the molten stream 

 flowed on to lower levels, leaving a vast cavern into which 

 the upper crust subsequently plumped down. 2 



1 The plain of Thingvalla is in a great measure clothed with birch 

 brushwood. 



2 I feel it is very presumptuous in me to hazard a conjecture on a 

 subject with which my want of geological knowledge renders me 

 quite incompetent to deal ; but however incorrect either of the above 

 suppositions may be justly considered by the philosophers, they will 



