228 BUKIAL OF THE KEMAINS CHAP. IV. 



the mould, from being washed down during 

 heavy rain, would have been thicker in the 

 lower than in the upper part; but this was 

 not the case in two out of the three trenches 

 here dug. 



In many places, where streets ran beneath 

 the surface, or where old buildings stood, the 

 mould was only 8 inches in thickness; and 

 Dr. Johnson was surprised that in ploughing 

 the land, the ruins had never been struck by 

 the plough as far as he had heard. He thinks 

 that when the land was first cultivated the old 

 walls were perhaps intentionally pulled down, 

 and that hollow places were filled up. This 

 may have been the case; but if after the 

 desertion of the city the land was left for 

 many centuries uncultivated, worms would 

 have brought up enough fine earth to have 

 covered the ruins completely ; that is if 

 they had subsided from having been under- 

 mined. The foundations of some of the walls, 

 for instance those of the portion still stand- 

 ing about 20 feet above the ground, and 

 those of the market-place, lie at the extra- 

 ordinary depth of 14 feet; but it is highly 

 improbable that the foundations were gener- 



