O'Eeilly — On Localities marked hy Earthquakes. 507 



I have now to show in wliat relation these lines stand. 



First, with the localities in Europe marked by earthquake action ; 

 and secondly, with similar localities outside Europe. 



In discussing the first point I shall confine my observations to 

 those lines which the method employed in recording the earthquakes 

 on the map has brought out prominently and distinctly, leaving aside 

 for the present the less well-marked lines and less clearly-defined 

 districts. 



The following may be pointed out as such well-marked lines : — 



I. — The Boundary Line of the Tertiary Formation of the Valley of 

 the Po. — This line meets the coast-line direction !N"o. 13 (east coast of 

 South America) at Novara, making with it an angle of 70°. It is 

 very remarkable by reason of the frequency of earthquakes along its 

 direction. On it are situated Pavia, Piacenza, Parma, Eeggio, Modena, 

 Bologna, Imola, Eaenza, Eorli, Eimini, Ancona — all frequently cited 

 on account of their earthquakes, the shocks either having been noted 

 in a single locality, or at several localities along the line. 



Its prolongations north-west and south-east, within the limits of 

 Europe and the coast of Syria, pass through many localities remarkable 

 for the frequency and intensity of their earthquakes. Thus, on the 

 north-west it traverses Mount St. Bernard, the Ehone at Tournus, the 

 district about Tours, and cuts the coast-line of Einisterre at Landernau, 

 an earthquake point. Towards the south-east it practically represents 

 the axis of the Adriatic, cuts the Albanian coast at Durazzo, the 

 Thessalian coast at Yolo (both well known by reason of their frequent 

 earthquakes), traverses the Sporades, cuts Bhodes at its northern point, 

 and the Syrian coast about Ascalon, crossing the Dead Sea at its 

 southern extremity. 



The coast-line between Genoa and Massa may be considered as 

 parallel to it, and roughly the coast-line between Pescara and Brindisi 

 on the east side of Italy. 



The coast-line from Ancona to Pescara may be considered as cor- 

 related with it by the angle 40°, as also the coast-line between the 

 Gulf of Policastro and Gulf of Santa Euphemia. 



II. — Marseilles, Toulon, and Laylach Line. — The coast-line direc- 

 tion and earthquake locus just considered meets at Parma the very 

 remarkable line extending from Marseilles and Toulon to Laybach, 

 over a distance of about 500 miles, well marked by repeated shocks, 

 sometimes local only, at others having extended along the whole line. 

 This line might in reality be considered as extending to Barcelona, in 

 Spain, and as regards correlation may be taken as making an angle of 

 80° with the east coast of England direction (No. 56). 



It might also be considered as parallel to the direction of the 

 Murcia earthquake zone, which, parting from near Almeria, is drawn 

 on the map at an angle of 70° with No. 6 (west coast of Africa). 



