220 The Mediterranean Sea 



low, and the water off it shallow, and there are few harbours. 

 The Adriatic stretches in a north-westerly direction for about 

 460 miles from its entrance between Cape Sta Maria di Leuca 

 and the island of Corfu to the Venetian shore in the Gulf of 

 Trieste. Its average width is about 100 miles. A ridge with 

 little over 400 fathoms appears to run across its entrance. 

 Inside this the water reaches a depth of 765 fathoms, but 

 shoals again rapidly towards Pelagosa Island, from which to the 

 northward, including quite two-thirds of the sea, the depth is 

 under 100 fathoms ; indeed no part of the sea within 150 miles 

 of its northern extremity is over 50 fathoms deep. There is 

 authentic historical evidence of the encroachment of the 

 Italian shores on the Adriatic, causing thereby a diminution 

 of its area. As a consequence many towns which were once 

 thriving seaports are now many miles inland; thus Adria, 

 which was a station of the Roman fleet, is now 15 miles inland, 

 and there are many similar examples. The large rivers Po 

 and Adige, which bring the drainage of the southern slopes of 

 the Alps to the sea, deliver large quantities of sediment in the 

 course of the year. The distribution of this mud is affected, 

 not only by its own weight tending to make it sink to the 

 bottom, but also by the set of the currents, which, running up 

 the eastern coast, turn to the westward and southward at the 

 upper end of the sea, and so tend to distribute the river mud 

 along the bottom in the neighbourhood of the Italian coasts. 

 The fact that towns which were formerly seaports are 

 now inland does not therefore necessitate the assumption 

 of a general rise of the land, it is merely a reclamation by 

 natural agencies of land from the sea at the expense of the 

 inland mountainous country. Precisely similar phenomena 

 are observed in the neighbourhood of the mouths of the Rhone 

 and of the Nile. 



Specific Gravity, Currents, etc. On the specific gravity 

 Dr Carpenter reports many and interesting observations. In 

 round numbers, that of the surface-water of the Atlantic off 

 the Straits of Gibraltar is 1-0260 to 1-0270, that of the western 

 basin of the Mediterranean 1-0280 to 1-0290, and that of the 

 eastern basin 1-0290 to 1-0300, while that of the Black Sea is 



