THE ADEIATIC PROVINCES. 



45 



wheels of numerous mills. Unfortunately the enormous mass of sediment carried 

 down by the river has foimed a bar at its mouth (see Fig. 37). No less than 

 39,200 cubic yards of siliceous mud are deposited every year, the river discharging 

 during the same period 686,000,000 tons of water. The temperature of this 

 copious spring averages 50° Fahr. ; that is to say, it is about the same as that of 

 the rain which falls upon the plateau 4,000 feet above. The temperature of all 

 the springs along the coast is analogous, and this proves that they are supplied by 



Fig. 27.— The Ombla, Gkavosa, and Eagusa. 

 Scale 1 : 81,500. 



li" 47 Eof Pans 



1 MUe. 



the rain precipitated upon the plateau of the Carso. Some of them rise from the 

 bottom of the sea. The most copious of these submarine springs gushes out at the 

 foot of the Monte Maggiore, and after heavy rain the rush of fresh water causes a 

 great commotion of the sea, dangerous to vessels entering within a circle of 600 

 feet radius. 



Phenomena of the same kind have been observed in connection with the 

 Istrian Arsa and the Dalmatian rivers Zermanja, Krka (Kerka), Cettina, and 

 Narenta. On a map these rivers, which hide themselves from time to time 



