414 Proceedings of the Royal Irkh Academy. 



The eruptions of Katla may be summarized as follows 



No. 



Date. 



Remarks. 



1 



894-934 approximately. 





2 



1245, 



Projection of cinders and water. 



3 



1262, 



Projection of mass of water, ice, and 

 stones. 



4 



1311, January 25, 



Accompanied by earthquake shocks. 



5 



1416, 



Considerable fall of ashes. 



6 



1580, August 11. 





7 



1625, September 2 to 14, . . 



The ashes carried to Bergen in Norway. 



8 



1660, November 3 to 12, . . 



Fishing-grounds of 38™ deep were filled 

 up by the eruption and formed a dry 

 beach. 



9 



1721, May 11, 



Great fall of ashes ; lasted during summer 

 and fall. 



10 



1755, September 10 to 16, 



Great projection of ashes ; lasted to 

 August 1756. 



11 



1823, June 26 to July 23, 



Not so violent as previous eruption. 



It may be remarked that of these eleven eruptions, five come within 

 the period covered by "Wolf's list. Taking them therefore from 1823 

 backwards, we get the following Table showing the correspondence of 

 the dates with those of the sun-spot list : — 



Erup- 







Inter- 



Sun-spot 



Differ- 



tions. 



Date. 





vals. 



dates. 



ences. 



11 



1823, June 26 to July 23, 



= 1822-50 



67-81 



- 1823-2 



0-70 



10 



1755, September 10 to 16, 



= 1754-69 



34-33 



- 1755-5 



0-31 



9 



1721, May 11, 



. = 1720-36 



70-53 



-H718-2 



2-16 



8 



1660, November 3 to 12, . 



. = 1659-83 



35-17 



-1- 1660 



0-17 



7 



1625, September 2 to 14, 



= 1624-66 





-f 1626 



1-34 



It may thus at once be remarked that nearly half the recorded 

 eruptions of Katla having well-marked intervals of years between 

 them, correspond j)ractically with the sun-spot period dates of "Wolf, 



