* VULCANISM, ETC., IN ICELAND. 511 



1807. Eruptions in the inhabited regions north of the Vatnajohull^ 

 from the 20th of August to the 5th September. Fall of ashes south of 

 the Vatnajokull, at Oraefi, and at Sudhrsveit. At the same time 

 " Jokellob" at Skeidhardrjokull. 



18G8. Towards New Year some volcanic phenomena at Mandreyjar, 

 in the north of Icehuid, were observed at sea in the neighborhood of 

 Tjorues; and at the same time an earthquake took place at Husavik. 

 In January, feeble shocks in the north ; on the 1st to the 3d November 

 earthquake shocks in the south. 



1872. Severe earthquake in the north, at Siisavik, on the 17th of 

 April. Several buildings were overthrown and others damaged. The 

 shocks were not discontinued until the end of May. In December of 

 the same year some feeble shocks w^ere observed in the north. 



1873. Eruption of the Kverlifjall {f) January 8 to 13. Considerable 

 fall of ashes in the south and east of the island. 



1875. Alternate eruptions of the Dyngju/jall and the Sveinagjd. To- 

 wards the end of 1874 some earthquakes were noticed in the northeast 

 of the island, and on the 3d of January a column of smoke was observed 

 to rise above the Dyngjvfjall, but this eruption did not cause any 

 damage. According to the researches of F. Jonstrup it issued from 

 craters situated in the southwest corner of the AsJcja, 94 meters below 

 the lava field of Askja, and 138 meters above the lake. These craters 

 emitted an enormous quantity of vapor even during the summer of 

 1876. During the first eruption large blocks of tuft and basalt, some 

 of a bulk of 31 cubic meters, were thrown to a height of 30 meters, 

 hnd one of them emitted blocks of gravel, cemented with ice, of a bulk 

 of 6 cubic meters. 



On the 18th of February occurred an eruption of the Sveinagjd, in 

 the M;('vatnsoraefi (desert of Myvatn), and the formation of several 

 craters ; on March 10, an eruption of 14 to 10 new craters, emitting 

 toiTcnts of lava; and on the 29th of the same month a violent eruption 

 of the DyngjufjaU. The entire eastern portion of Iceland became 

 covered with ashes and pumice stone, the bulk of the latter having 

 been estimated at 400 millions of cubic meters. Portions of the ashes 

 were transported to Norway, and even at Stockholm and its vicinity 

 a shower of the ashes fell on the evening of the 29th of March. This 

 eruption issued from the most southerly crater of the valley of Askja, 

 to the northeast of the pit mentioned before. The ground all around 

 was, in 1870, covered with pumice stones, the larger ])ortion of them 

 having a diameter of 15 to 20 centimeters, and many of 50 to 100 cubic 

 decimeters in bulk. At one place where they were of a thickness of 

 00 to 100 centimeters they had entirely hidden a bed of snow of 8 

 meters' thickness, formed during the winter of 1874-'75. Ou the 4th 

 of xVpril several eruptions were observed on the My vatnsoraefi, and ou 

 the 15th of August the last one occurred, none of them causing much 



