84 



last year, specimens of which were upon the table before them. 

 Of the stony streams of lava they had two very good examples ; 

 first, the huge lava streams which flowed from Skeptar JokuU 

 in 1783, being 50 miles long and 25 wide, and the other 40 miles in 

 length and 7 broad, being in some places 500 feet in depth. It had 

 been computed that the entire mass exceeded in bulk that of JMont 

 Blanc. This lava was balsatic and highly ferruginous, and impreg- 

 nated very strongly the waters of the river Eldvatn, which flowed 

 through it. The second example was the lava stream which had 

 flowed into the far-famed valley of Thingvilla, wherein the Althing, or 

 Parliament, of Iceland used to hold their meetings, and the wonderful 

 rifts of the Almanna-gjk and the Raven's-gjk occurred. At some 

 remote period of the geological history of Iceland a large river of 

 lava flowed from Mount Skjaldbreith, which was about 30 miles 

 distant, into the valley of Thingvallir. A crust, of course, soon formed 

 on the surface, and, upon the cessation of the eruption, the still 

 liquid lava at the bottom of the stream continued to flow into the 

 deeper parts of the lake, which occupied the S.E. end of the valley 

 of Thingvallir, leaving the unsupported crust, which was now of great 

 thickness, to sink down to the present level of the valley, occasioning 

 lateral rifts upon either side of the stream— viz., the Almanna-gjk on 

 one side and the Raven's rift upon the other. The valley of Thing- 

 vallir was likewise traversed by many smaller fissures and crevasses, 

 which in many instances enclosed and almost insoculated large masses 

 of lava ; the Loghsberg, or " hill of laws," was such an island of rock, 

 and was rendered inaccessible except at one point by deep yawning 

 crevasses. It was on account of these natural fortifications that it was 

 chosen as a forum for the ancient Court of Althing, which assembled 

 there once a year. Such were the monuments of Iceland, which took 

 the place of the ruined castles and abbeys of other countries, 

 simply the rude rocks of Nature ennobled by brave deeds of history or 

 some touching romance of love. 



They next came to the hot springs of Iceland. The chief of these, 

 par excellence, was, of course, the Great Geysii-. It had been so often 

 described and redescribed that it scarcely needed a remark from him. 

 Professor Forbes calculated its age, from the thickness of siliceous 

 scinter which surrounded its basin, at 1,000 years. The Great Geysir 

 was surrounded by numerous other springs of all temperatures and 

 sizes, whose deposits differed according to the character of the rocks 



