SOIL OR SURFACE-MATTER. 235 



of the inhabited portion, an open space of the street 

 being between them and the city walls. It was, 

 however, very singular that these indications, though 

 correct, were not verified till the ground had been 

 excavated to a depth of five or six feet ; and before 

 the actual base of the wall and the floor of the street 

 were reached, a tall labourer was entirely hidden from 

 view. The first foot or two may be accounted for by 

 the rubbish when the place was destroyed, but as no 

 soil is likely here to have been brought down by floods, 

 we are almost obliged to attribute the remaining 

 four or five feet to the annual addition of vegetable 

 mould. The excavation above referred to is not the only 

 fact which indicates a great accumulation of soil ; a 

 handsome tesselated pavement lately discovered in 

 the churchyard was four or five feet below the present 

 surface," &c., &c. T This is a startling fact in favour 

 of the growth of soil by vegetable decay; and Mr 

 Lee further states, in a subsequent communication 

 on the subject : " The old town of Isca is on a tongue 

 of land slightly above the flats on the rivers' banks 

 (the Usk and the Avon Llwydd), and from the situa- 

 tion there is no chance whatever of any earth being 

 brought down from the hills to the place I mentioned." 

 Although the growth is so large in the aggregate, yet 

 the yearly amount when calculated seems moderate 

 enough. It must be about 1700 years since the 



1 Keller's "Lake Dwellings," p. 367. 



