ox THE AFTER-SHOCKS OF EArvTHQUAKES. 



199 



TABLE XXI.-YEARLY SEISMIC " ACTIVITIES" IN SWITZERLAND, 



THE VESUVIAN DISTRICT, SICILY, AND THE BALKAN PENINSULA 



AND NEIGHBOURING ISLANDS, 5'ROM 1865 TO 1883. i 



1. The data are taken from Fuchs' " Statistik der Erdbeben." It is difficult to count ex- 

 act numliers of earthquakes from the Catalogue, and the figures in the table, wliich are intend- 

 ed to represent seismic " activities," are merely the nuuiljers of days in successive years on which 

 one or more shocks have lieen recorded. 



