508 ■ SCIENTIFIC RECORD FOR 1885. 



struck the tVozeu grouud at Naefrholt with such force that it could only 

 be removed with the aid of a lever. Masses of i)uniiee stone caused 

 the Ytri-Raug^ to overflow its banks, and the Thjorsa and other rivers 

 carried enormous quantities of it out into the sea. A current of lava, 

 7,500 meters long, spread out towards south -so nth west. On the 21st 

 of April the ashes measured 5,000 meters in height and still rising. 

 This eruption did not end until the next autumn. 



1774. Eruption in an unknown section in the vicinity of the SJcei- 

 dhardrjolcull. 



1783. Eighth submarine explosion southwest of BeyJcjanes in May. 

 An island formed with a crater which emitted such quantities of pum- 

 ice stone that the sea was covered with it to a distance of 150 to 225 

 kilometers. This island, which received the name Nyo (new), soon 

 again disappeared. 



In the same year grand eruptions took place in tbe vicinity of tlie 

 source of the river Slcaptd. On the first of June a trembling of the eart ii 

 was noticed throughout Skaptafellssyssel which lasted until 8 a. ni. 

 At 9 A. M. a violent eruption was noticed at Sidha in a direction north. 

 At the same time the Skapta, then 130 meters wide, commenced lo 

 diminish rapidly, and on the 11th June it had dried up entirely. Vu 

 the 12th a current of lava precipitated itself like a roaring sea into the 

 bed of the river, 160 to 190 meters deep, and after filling it up com- 

 pletely, overran its banks, spread in various places and encircled 

 several farms, but was suddenly arrested by a deep pit existing in the 

 bed of the Skapta between the farms of Skaptardalr and the A, and 

 which it would have to fill and bridge over before being able to pursue 

 its course. The emissions of lava continued without interruption, and 

 in the direction of tJlfarsdalr and Varmdrdalr twenty-two columns of 

 fire and ashes could be counted. From the 14tli to the 22d June the 

 lava currents overflowed each other in the plains south of the Skapta, 

 destroying several farms and fusing the old lava, at the same time 

 obstructing or dislocating several water courses. Pumice stones and 

 dross were thrown a distance of 113 kilometers westerly to Eangar- 

 vallasyssel. On the 30th of June a current of lava turned west, towards 

 the Kudhafljot, one of the largest rivers of Iceland, which arrested it 

 in its course, the current of lava being unable to surmount this power- 

 ful barrier. The east branch of this current emptied itself into the 

 Skapta, bridged over on the 17th of July a deep pit below the cascade 

 of Stapafoss, and stoj)ped on the 20th of July at 1,900 meters from 

 Kirkjubaejarklaustr, where it filled a channel of 130 meters in width 

 and 40 meters in depth. The volcanoes continued their eruptions with 

 diminishing force during the months of July, August, and September, 

 and even in the middle of January of the next year one could still 

 observe from Skaptartunga feeble eruptions behind the mountains. On 

 the 29th of July, 1783, new eruptions were again observed farther to 



