One of the things that made a deep impression about how water is seen by our earlier ancestors was in fact a camcorder moving picture made by Pete.... He had captured that rare moment when the water rushes over the drybed of the river, rising through the dry chalk and cascading down - a life giving and magical force, a special event. Its strange how Burl misses out on water, when he describes so acutely in "Rites of the Gods" the symbolic nature of the lives of these people.. but as I am only half way through the book perhaps I have'nt got to it. I suspect that the Swallowhead Spring is ancestral to Silbury, in the sense that it is remembered as a first settled place..