Needles of Stone Revisited
Gothic Image (Glastonbury, England), 1986; ISBN 0-906362-07-5
Now out of print, but available for free download:
- HTML format, from the Glastonbury Archives site
- MSReader .LIT format
, from Ken Mattern's ESSPC-EBooks site 
Originally published as Needles Of Stone by Turnstone Books back in 1978, with a mass-market paperback by Granada Publishing, this revised edition is essentially a reprint with more footnotes and an addendum bringing it up to date (at the time), with particular reference to the Dragon Project research on physical energies (infra-red, ultrasound, microwave, cosmic-radiation anomalies and so on) at stone circles and similar sites.
It's become something of a classic, particularly for the new breed of feng-shui practitioners, as it's almost the only book which looks in detail at the level beyond systems, to a deeper understanding of what 'earth-energies' actually mean. To quote the book's cover-copy:
"This book is a search for a magical technology: the elusive 'earth-energies' connected with standing stones and other sacred sites. As Tom Graves puts it, "it is a study in ideas, an attempt to put some of the ideas that have arisen in the 'earth-mysteries' field into a coherent shape or form, to place them in a context that makes practical sense at the present time".
Combining original research in dowsing with a review of many different aspects of the sites - from archaeology to geomancy and magic, from physics to ghost-hunting and parapsychology - the book shows that we need to look at them not so much in terms of the past, but in the effects and reality of those earth-energies now. It ends with a call for a re-assessment of the pagan view of reality, to see where its experience can be of value in our present over-civilised world.
This revised edition of Needles of Stone includes a new chapter on developments over the past decade, including a summary of the important Dragon Project research and its implications for our future."