Chai'. IV. OF ANCIENT BUILDINGS. 225 



its dark colour and in its texture from the 

 underlying sand or rubble. In the specimens 

 sent to me, the mould resembled that which 

 lies immediately beneath the turf in old 

 pasiure-land, excepting that it often contained 

 small stones, too large to have passed through 

 the bodies of worms. But the trenches above 

 described were dug in fields, none of which 

 were in pasture, and all had been long- 

 cultivated. Bearing in mind the remarks 

 made in reference to Silchester on the effects 

 of long-continued culture, combined with the 

 action of worms in bringing up the finer 

 particles to the surface, the mould, as so 

 designated by Dr. Johnson, seems fairly well 

 to deserve its name. Its thickness, where 

 there was no causeway, floor or walls beneath, 

 was greater than has been elsewhere ob- 

 served, namely in many places above 2 ft., 

 and in one spot above 3 ft. The mould was 

 thickest on and close to the nearly level sum- 

 mit of the field called " Shop Leasows," and 

 in a small adjoining field, which, as I believe, 

 is of nearly the same height. One side of 

 the former field slopes at an angle of rather 

 above 2°, and I should have expected that 



