Dr J.D.  Wilcock 
22 Kingsley Close, 
STAFFORD, ST17 

January, 1993


The Editor, Descent, 51 Timbers Square, Roath, CARDIFF, South Glamorgan CF2 3SH

Dear Sir,

Dowsing questions

Angela Garwood has raised some questions about dowsing in Descent (109).  Since she
has also referred to my lecture 'On the possible scientific justification of
dowsing for the detection of caves' at the Bradford BCRA Conference, I feel
that I should comment further.  I will begin by restating that I am an
agnostic about the mechanism of the dowsing method for detecting flowing
water and large underground cavities, but that I believe the observed
movement of the dowsing rods to be caused by an involuntary muscular
reaction initiated by an electric, magnetic or electromagnetic field effect
which is detected as a gradient by two glands in line with the spinal
column, the pituitary gland (at the base of the brain) and the adrenal gland
(in the kidney region).  My own experiments are confined to limestone
regions, and to the detection of hydrological systems and caves beneath
featureless terrain.  I can report considerable success over many years,
including the diving route at Alum Pot; East Kingsdale Master Cave route,
and the new route north from West Kingsdale towards Yordas Cave; the
direction of the Gingling Hole extensions; the Dub Cote/Brackenbottom Water
Supply/Douk Gill/Brants Gill route, which must be the main drain for the
Fountains Fell water; the predicted r oute for the Tarn Sinks water via
Malham Cove then South West and south to Aire Head Springs (this is
particularly interesting in view of the new dye test results reported in
Descent 109); the detection of some passages in Slaughter Stream Cave,
before their subsequent exploration; and latterly dowsing to determine the
site for Hymac digging (White Pit, reported in Descent 109, being a notable
success).  All these exercises were carried out before exploration confirmed
them; I fail to understand the antagonism of some divers and cavers to the
dowsing method, and to my work in particular, since I am in no way trying to
belittle their magnificent achievements, and I have nothing but admiration
for their work.

Now to Angela's specific questions:

1.  Dowsers, being essentially self-taught, exhibit a wide variety of methods of
working, and so I can only report on my own methods and observed reactions.  I
always see a positive reaction (wires cross) over a cave or flowing water, and a
negative reaction (wires open) when crossing the boundary of the reaction going
outwards, i.e.  away from the centre-line of the cave passage.  The width of the
positive reaction can be 100m or more.  The rule of thumb used by many dowsers is
that the cave passage lies below the centre-line of the reaction, at a depth equal
to half the total width of the reaction (this would agree with the known behaviour
of magnetic lines of force above a magnetic anomaly, hence the supposition about a
magnetic origin for the effect).  However, I have also seen a wide reaction being
caused by a wide bedding plane cave much nearer to the surface than the depth
predicted from the rule of thumb.

2.  The intensity of the reaction in my experience seems to be caused by the amount
or speed of flowing water, for example strongly pumped water in large pipes at a
water supply depot caused very strong reactions.  I have observed what I call the
'wild water' effect over underground rivers, a quite different reaction to the quiet
and steady effect observed over large dry passages.

3.  Correlations of dowsing results with a variety of man-made and geological
features have been made, the actual features being unknown to the dowsers before the
exercise.  A reversed (negative) reaction was observed over faults, and positive
reactions over buried foundations and filled trenches.  Accumulated water at the
junction of a saturated sand layer and underlying clay gave a positive reaction.
Significantly for the location of caves, brick culverts carrying streams and rivers
under the streets and buildings of a town give strong positive reactions.  Indeed,
those cavers who took part in the practical workshop in Bradford City Centre
following my lecture at the conference detected a stream flowing in a brick culvert
which was followed for about 1km to a building site where the surface stream and
entry to the culvert was plain for all to see - proof enough?

4.  It is important, however, to realise that the dowsing reaction is a
three-dimensional effect, not just the plotting of a corridor on a two-dimensional
map.  Thus dowsing in caves can detect passages or underground streams which cross
below or even above the passage in which the caver/dowser is currently walking (as I
have shown in Carno Adit).  This may account for Angela's observation of a positive
reaction on the ground floor of a building and a negative reaction (edge effect?)
over the same spot on the first floor.

I will conclude my letter with the following opinions:

a) The dowser is endowed with a subconscious cognitive faculty which results in
unconscious muscular reaction, accompanied by a nervous sensation (described by
different dowsers as tingling "like an electric shock", a chilly sensation,
shivering, trembling, or an unpleasant sensation in the stomach).

b) The mechanism for detection is possibly electric or magnetic in nature, since
good insulation from the ground (rubber boots), good conductivity in the region of
the kidneys (drinking beer!), and high skin conductivity (sweaty palms) all lead to
enhanced reactions.  The effect seems to be enhanced by fast walking, and seems to
be removed by blindfolding (perhaps sight is part of the unconscious positive
feedback mechanism?).

c) The detector sites seem, from magnetic shielding experiments, to be in the
regions of the adrenal gland (between the kidneys) and pituitary, or pineal, gland
(at the base of the brain).

d) What is required is the development of a general theory which will permit
scientists to incorporate the mechanism into scientific knowledge.

e) Meanwhile, the method should continue to be employed:  it will ultimately be
validated by its accuracy and practical value, rather than by theories and opinions.
After all, the lack of a theory to explain gravity or magnetism prevents neither our
use of hydroelectricity (generated from gravitational potential energy), nor of
electric motors (which use artificial magnetic fields).


John Wilcock, Stafford