Hi Old Bob,
Bishop's Rule
This passage is taken from Chapter 2 (Dowsing & Archaeology) from Tom Graves' book 'Needles of Stone'.
http://www.isleofavalon.co.uk/Glastonbu ... ontnt.html
'Underwood uses the term 'parallel' for an image version of the so-called 'Bishop's Rule', a depth-finding technique that has been used by dowsers for centuries. Underwood's 'parallels' run parallel to the water-line and separated from the centre of the apparent line by a distance approximately equal to the depth of the water-flow at that point; while the Bishop's Rule states that if you walk outward from directly above the centre of the water-line, you will get a second reaction of your dowsing-rod at a distance out that coincides with the depth of the stream at the point which you started from. In both cases the rule is that
'the distance out equals the distance down'; Underwood's 'parallels' can be seen as the loci derived from measuring the Bishop's Rule outward from an infinite number of points on the water-line. Underwood's 'flow-lines' are small feathery lines, usually S-shaped, formed on both sides of the water-line; they 'follow' the apparent strength and direction of flow, rather like the eddy-currents formed in still air by the passing of a car.'
Regarding your comments about the Masons, don't forget that many unenlightened twits still regard dowsing as being linked to the 'Devil' as they regard a dowser as some kind of witch and follow the biblical instruction of "Thou shalt not suffer a witch to live" although that does conflict, in some minds with the Commandment - "You shall not murder". Many are also simply afraid of what they don't understand or what they cannot prove scientifically.
