508 Proceedings of the Royal Irish Academy. 



To tlie "west this Marseilles-Laybach. line cuts the Spanish, coast at 

 Cadiz ; to the east it passes through Hungary, running about thirty 

 miles north of the Balaton Lake, and parallel to its axis. It passes 

 at Pesth, runs parallel to and to the north of the earthquake line 

 which extends from Kardzag to Szathmar iN'emeths. It there meets 

 the earthquake line which extends from Lemberg in Gallicia to Her- 

 mannstadt in Transylvania, making with it an angle of about 70°. 



III. — Ea&t Coast of Sardinia Line. — At Parma the two last de- 

 scribed directions are intersected by another, equally well marked — 

 that is, the line represented by the east coast of Sardinia, drawn on the 

 map at 80° with the north coast of Africa (No. 14), but which might 

 also be considered as a parallel to the east coast of Sweden direction 

 {'Eo. 51). 



This east coast of Sardinia direction passes through Elba, runs 

 parallel to the Leghorn coast-line, passes at Parma, between which 

 city and Leghorn simultaneous shocks of earthquakes have frequently 

 occurred, follows the west side of the valley of the Adige, and touches 

 in its extension the western side of the Saxony earthquake district. 



lY. — East Coast of Siceden Direction. — This direction, nearly 

 parallel to the last described, is much more distinctly marked in its 

 characteristics as a line of eai'thquake action. 



Its correlation with the great circle coast-line directions is 40° with 

 IS'o. 50 (Promontory of jN"ew Ulster). 



That portion of it extending from JS^ordkoping to Karlscrona is 

 well marked by its rectilineal direction. Farther south it passes at 

 Prague, Undine, Eimini, and mouth of the Tiber ; traversiag the 

 Tyrrhenian Sea, it cuts the African coast at Cape Bon and at Sfax. 

 As regards this portion of the line, it may be remarked that up to the 

 present (23rd July, 1881) there had not been recorded (in the lists 

 consulted) any earthquake as having taken place along this coast of 

 Tunis, although theoretically the extensions of the coast-line dii'ections 

 already described would point out this countiy as one of earthquake 

 action. !Row, owing to the presence of scientific observers in this 

 country, within the last month or so we receive intelligence of an 

 earthquake or earthquakes having taken place in and about the Gulf 

 of Gades ; and, furthermore, notice of the fact that the constitution of 

 the country is volcanic. I cite this fact to show how those Knes may 

 be interpreted as regards districts but little explored. 



The section of this line between Ptome and Eimini is one of the 

 best-marked earthquake lines in Italy, while the section between Pola 

 and Briick is also well defined as a direction by a series of poiats along 

 which shocks have been continually occurring. Between Palermo and 

 Naples a parallel to this coast-line direction seems to be marked out 

 by earthquake movements, cited as having extended from one point to 

 the other (April 16, 1817). 



