THE HUMAN BPBGIBS. 137 



the basin of Xeuwied. The delta of the last-named river is 

 of considerable size, with a gradual but slow progress in the 

 sea; it having been demonstrated, by measuring the distance 

 between the fossa Marians and the sea, that from the til 

 Marina to the present, a period of near ars, only about 



1000 yards have been added to the shore. 



HALT. 



1' -sing, for the present, the Alpine system without notice* 

 we arrive ;it the Italian peninsula, reposing, in its wl. 

 upon an ignited gallery, in perpetual activity, and producing a 

 sea more fathomable than the abysses of the Gulf of Lyon 



offing. On the Tyrhenian coast, the changes 

 most readily ascertained occur at the port and city of Pisa, 

 which were originally situated at the mouth of the Arno, 

 when re now above lour miles inland ; and the Au-ar 



streamlet, which, according to Strabo, fell into the river close 

 to the town, now terminates ten miles distant. The rolcanic 

 soil, alike fertile and deleterious in the maremmas, is in some 

 places unstable, so that, even since the fall of the Ri 

 empire, certain spots about Bais have been sunk below the 

 level of the sea, and again raised up above it, without entirely 

 overturning columns, such as those of the temple of Serapis, 

 all of which, at a certain elevation above their base, have been 

 subjected to the boring of Lithodomi, while other parts of 

 the ancient city, an 1 a paved road, are seen beneath the waters. 

 The whole length of Italy exhibits craters, lakes simmering, 



* Reniarknl.lc, however, f"r land slips, anciently more numerous and 

 extensive than at present. In the Alps, fragments of Roman roads, with 

 arched gateways, occur among elevated precipices. Hannibal encoun- 

 tered a subsidence of the road on his passage. Those of Mont Grenier, 

 Diablerats, Mont Chede, and particularly of the Rossberg, in 1806, are 

 well known ; and that of Cernaus, hetween Dijon and Pontarlier, in the 

 Jura, where the high road sank 300 feet, in 1839, is the last of irnport- 

 auco. 



1U- 



