THEORY OF THE EARTH. 181 



of 20,000 metres* from the meridian of Adria ; and 

 the southern mouth, which had taken possession 

 of the canal of Toi, was then 17,000 metres^ ad- 

 vanced beyond the same point. Thus the shore 

 had become extended nine or ten thousand metres^. 

 to the north, and six or seven thousand to the 

 south. Between these two mouths there was 

 formerly a bay, or a part of the coast less ad- 

 vanced than the rest, called Sacca di Goro. During 

 the same period of four hundred years previous to 

 the commencement of the seventeenth century, the 

 great and extensive embankments of the Po were 

 constructed ; and also, during the same period, the 

 southern slopes of the Alps began to be cleared 

 and cultivated. 



The great canal, denominated Taglio di Porto 

 Viro, or Podelle Fornaci, ascertains the advance of 

 the alluvial depositions in the vast promontory 

 now formed by the mouths or delta of the Pb. In 

 proportion as their entrances into the sea extend 

 from the original land, the yearly quantity of allu- 

 vial depositions increases in an alarming degree, 

 owning to the diminished slope of the streams, 

 which was a necessary consequence of the prolon- 

 gation of their bed, to the confinement of the 

 waters between dikes, and to the facility with 



* Or 21,372 yards. Transl. 



f Or 18,591 yards Transl. 



} Equal to 9,842 or 10,936 yards. Transl. 



^ Equal to 6,564 or 7,655 yards Transl 



