ON THE AGE OF STONE CIRCLES. lO? 



(b) Cutting /., Fosse. — This cutting was 24 feet long, the most 

 westerly margin being about 156 feet from the middle of the hedge along 

 the road at the Kennet Avenue entrance. Turf was removed to a width 

 of 26 feet in the first instance, but this dimension in some places had to 

 be increased to 45 feet in order that the profile of the fosse, when partly 

 re-excavated, might be shown to better advantage. 



In plotting the sectional diagram it was found that the present surface 

 of the silting of the fosse in this part was approximately 14 feet lower 

 than the original ground level above it (viz. the level of the adjacent 

 field in which the remains of the outer circle of stones are to be seen) at 

 the time of the construction of the fosse. It is rather remarkable that 

 the Avebury fosse has not silted up to a greater extent.' 



As it was anticipated that the fosse might pi'ove to be deep, ledges 

 had to be left in the silting at different stages to allow of the material 

 being thrown up from the lower levels with comparative ease ; and it was 

 found necessary in a large cutting of this sort to wheel out nearly all the 

 material on planks. 



The turf and turf-mould was found to reach to a depth of 0-8 foot ; 

 in it several modern shards and scraps of iron were found. We next 

 came to a fine gritty mould, which has been called ' surface silting.' The 

 average depth of this in the middle was 3'3 feet from the surface, tapering 

 oQ. towards both sides of the ditch. In removing this layer horizontally 

 we, of course, came to earlier deposits on the sides, viz. mixed silting and 

 chalk rubble. As will be seen by the diagram, the strata ai-e deepest in 

 the centre of the fosse, the surface of each deposit, as viewed from above, 

 jDresenting a decidedly concave outline. The deeper a ditch, the more 

 pronounced one expects to find this chai'acteristic. Silting falling into 

 an open ditch from either side naturally covers the sides very rapidly, 

 and the surface of the silting as it increases from bottom to top is always 

 concave, more so in the early stages of filling than later. 



The next deposit — mixed silting, consisting of mould with a larger 

 proportion of small pieces of chalk — extended to an average depth of 

 8'7 feet in the middle of the silting. This deposit was also on the curve. 

 In most places the bottom 2 feet of this silting was found to be of a finer 

 kind with a smaller admixture of bits of chalk, and it is differently repre- 

 sented in the diagram. 



When the middle of the mixed silting was reached we proceeded to 

 trace the hard chalk walls of the fosse on both sides to the depth we had 

 excavated. This done, the work from day to day became temporarily 

 checked by the caving-in of parts of the vertical face of the silting, some- 

 times two or three tons falling in one night. This is well seen in the 

 photographs. In the mixed silting, at depths of 5, 6-3, 6-3 and 7 feet 

 respectively, four sarsen boulders were found, each about 2 feet across. 



The mixed silting proved to be an interesting deposit as far as 

 fragments of pottery were concerned. Four distinct qualities v;^ei'e found, 

 representing three definite archaeological types. In the upper third, and 

 above a depth of 4-5 feet from the surface, Normaii and Early English 

 pottery was found commonly, indicating not only that Avebury was 

 overrun during those times, but also that since early Norman times about 

 4-5 feet of silting had accumulated in this part of the fosse. Secondly, 



' I heard some reports that the fosse had been cultivated as arable land some five 

 ftr six decades ago, but I was unable to substantiate those statements on making 

 inquiries from old inhabitants. 



