412 



DISCOVERY OF A CIST. 



constructions practically where they were thrown by the con- 

 structors except for one thing. There is evidence that they 

 have been washed into cavities between the stones and into 

 the graves. 



The black mould is of considerable depth in the gardens 

 behind the low stone wall on the West, and the levels show 

 that the blown sand, which must have covered these gardens, 

 has been removed until the black earth was reached. 



This black mould covered the whole of the ancient beach, 

 for openings made on the South, East and North all proved 

 that the pebbles were black and the interstices were permeated 

 by the black vegetable mould. 



This black mould was very visible on the floor of 

 the first circle and attracted the attention of the workers. 

 Later on the earth which covered the small grave on the 

 North side was found to be black, and a quantity of black 

 material formed a thick layer of horizontal structure which 

 looked so much like burnt bone that the workmen were 

 directed to cease work on that spot so that its nature might 

 be determined. 



It was found to be vegetable humus, or rather it was a 

 partly decomposed vegetable mould with both humus and 

 fragments of plants. The portions of plants had retained 

 their woody structure and their carbonaceous character because 

 they were protected from oxidation by a layer of compact 

 clay. 



This black earth was therefore on the site before and 

 when the stones were erected. 



We have no evidence at all that the dolmen build- 

 ers covered their structure with a mound of earth. This 

 was usual, at all events for late structures, but the mound 

 we found over these stones was not placed there by man. 

 The evidence is all against that theory. 



The constitution of the mound was as follows : — 



3. — (1st) The lowest level was largely composed of the 

 black earth and blackened pebbles belonging to the beach. 

 These were also found within the. enclosures and graves. 

 A small remnant has been left in position by the excavators. 

 ( 2nd) Superimposed on this black layer was a mound of clay 

 and decomposed gravelly deposit of varying thickness but 

 averaging 5 feet. This began above the level of the tops of 

 the smaller graves and filled up the dolmen and was rain- 

 washed into a more or less conical hill. This clay mixture 

 was stratified everywhere with horizontal strata, interlined 

 with black vegetable lines — just as is the sandy deposit at 



