20 ON THE PARALLEL ROADS 



presented in a section of the valley, supposed to be taken 

 across from B to E of the plan, and given in fig 3., in which 

 G represents the river. High up, on the face of the hills on 

 the south side of the valley, are the remains of the Baths of 

 Nero, (E in the plan, fig. 4. and section, fig. 3.), and the re- 

 mains of the mouth of the Aqueduct by which Afpius Clau- 

 dius conveyed water into Rome, from the lake, which origi- 

 nally filled the valley to that height, (F, fig. 4.) On a level 

 with these, and consequently on a level with the ancient lake, 

 an exact, and perfectly horizontal shelf, in every respect resem- 

 bling those of Lochaber, runs around the face of the hills on 

 the southern side of the valley, as expressed by the dotted 

 line, fig. 4. But on the northern side, (where B, fig. 4. marks 

 the situation of the convent of Santa Scholastica, and C that 

 of San Benedetto), there is a great deal of rock, and conse- 

 quently no such appearance of a shelf is to be observed. At 

 the head, or western extremity of the valley, (D, fig. 4.) the 

 river enters it through a ravine, by rapids, and over a cascade. 

 Such is a description of the present state of this singular spot, 

 to which I must beg particular attention, as it will be found 

 to have a wonderful resemblance, in all its parts, to some of 

 the appearances, to be described in the sequel of this paper. 

 The Valley of Subiaco was anciently filled with part of the Si/n- 

 bruina Stagna ; and the name of Siiblacum was given to the an- 

 cient town, from the circumstance of its being situated under the 

 lake. Of the Simbruina Stagna, anciently three in number, none 

 are now remaining. This was the lowest ; the other two were 

 formed by the river higher up, and it is very probable, that 

 some intei-esting appearances, of a similar nature to those I 

 have been describing, may likewise exist on the sides of the 

 hills which served formerly to confine them. But the banks 

 of the Aniene are little known above the valley of Subiaco, 

 the country being so overrun with banditti, that there is no 

 safe travelling beyond the Convent of San Benedetto, where, 

 indeed, the regular road stops. These lakes are more than 



once 



