THE SURFACE OF THE GLOBE. 81 



of the bridges and roads, has communicated to me his valuable re- 

 searches explanatory of these changes in the shores of the Adriatic. 



Extract from the Researches of M. De Prony, on the Hydraulic 

 System of Italy. 



("An Account of the Displacement of that Portion of the Banks of the Adriatic 

 Sea occupied by the Mouths of the Po.") 



" That part of the coast of the Adriatic comprised within the 

 southern extremities of the lake or lagoons of Comachio and those of 

 Venice has undergone since early times many changes, attested by 

 many veracious authors, and borne out by the present state of the 

 soil in the districts on the coast ; but it is impossible to detail with 

 precision the successive progress of these changes, and particularly the 

 exact measures, previously to the twelfth century of our era. 



" We are however sure that the city of Atria, now Adria, was 

 formerly situated on the sea coast; and this gives us a decided and 

 known point of the primitive shore, whence the shortest distance to 

 the present shore, taken from the mouth of the Adige, is 25,000 

 metres*, (15^ miles and upwards). The inhabitants of the city have 

 formed very exaggerated notions, in many instances, on the antiquity 

 of this city ; but it cannot be denied that it is one of the most ancient 

 in Italy : it gave name to the sea which washed its walls. By some 

 excavations made there and in the vicinity, a stratum mixed with 

 relics of Etruscan pottery has been discovered, in which there is no 

 mixture of Roman workmanship ; the Etruscan and Roman are found 

 mingled in an upper stratum, above which the vestiges of a theatre 

 have been found. Both layers are very much below the present soil. 

 I have seen in Adria curious collections, in which the relics that they 

 contain are arranged separately. The prince viceroy, to whom I 

 observed how interesting it would be to history and geology if a 

 research were made into all the excavations of Adria, as well in the 

 primitive soil as in the successive alluvial deposites, seemed much 

 struck with my suggestions but I am not aware if they have been 

 carried into effect. 



" On leaving Atria, which was seated at the bottom of a small gulf, 

 we find, in following the line of coast to the south, a branch of the 

 Athesis (Adige), and the Fossa Philistina, of which the remaining 

 trace corresponds with what might have been the re-union of the 



* We shall find that the farther extremity of the alluvial promontory formed by the 

 Po, has advanced into the sea farther by ten thousand metres (6^ miles nearly) than 

 the mouth of the Adige. 



VOL. I. K 



