b"Divination: A geophysicist's viewFeatureAn elegant, thorough and entertaining discussion of the divining rod and dowsing was presented over 100 years ago by Arthur Ellis in a Water Supply paper of the US Geological Survey. He cited 570 publications on the subject in the French, German, and English literature from 1532 to 1917. These vividly attest to the continuing interest and curiosity of practitioners, promoters, believers, scientists and sceptics in such matters, unabated to this day. An internet search now readily reveals over 50 references to commentaries, field tests, denunciations, and justifications of the method since Ellis summaries. Noteworthy among these is the Australian Skeptics series of tests carried out in Perth (WA) and Gosford (NSW), arranged by James Randi and Dick Smith during 1980. No diviner was able to claim a $40 000 prize for the better-than-chance locating of buried targets: water in a piped water grid, a box of brass, and an ingot of gold.No report to date has convincingly demonstrated that divining is a reliable technique nor that the dowsers success rate is any better than random chance outcome. One can discount the apparent triumphs of water witching in extensively alluviated farming areas, where information on water tables and aquifers is usually known, or if not commonly known, is available on enquiry in the files of local and state government rural departments. However, it is acknowledged that divining rods or twigs do move in the hands of some practitioners, and the relevant question for us is how do these movements occur? What is divinings secret? What makes a dowser? To this end some simple field tests were carried out, and the basic physics considered.Field experiments with Y rodsEight divining rods were made for field testing. These are shown in Figure 10. The test site, 70 km NW of Sydney NSW, was previously documented in the Environmental Issue of Exploration Geophysics (23, 4). This 1992 field work entailed magnetic, transient electromagnetic, and resistivity responses in traverses directly over and near shallowly buried 50 L and 200 L steel drums in Areas A and B of a test site in Hawksbury Sandstone terrain. These targets were located readily by magnetics, with anomalies of the order of 10s of nT. Transient EM also gave clear indications; resistivity less so. The point of this exercise is that it permits comparison of rod responses with geophysical data from known subsurface metallic sources. The drums are in high, dry, barren, sandy gravel and still in good condition (magnet check), so it is assumed that similar geophysical responses would be obtained if the surveys were repeated now. Traversing with the divining rods (Figure 11) gave no indications whatsoever i.e. no dipping, twisting, or other movement over or near drums. All eight rods were used, in turn, each held 1 m above ground.A leaking fresh water dam north of the test paddock hadFigure 10.Divining rods constructed for field experiments. Top (left to previously been investigated by me with spontaneous potentialright): no.1 steel, very high magnetic susceptibility (~130 SI), 165 gm mass; field equipment. A positive SP anomaly of 25 mV was foundno.2 fencing wire, high magnetic susceptibility, 47 gm; no.3 stainless steel, non-magnetic, 176 gm; Middle (right to left) no.4 grey gum, 115 gm; no.5 around the seepage outlet. The Y rods did not move here either. yellow bloodwood 18 gm; no.6 jacaranda, 26 gm; Bottom orthogonal rods, I did notice one effect that has been reported by others, butno.7 stainless steel, non-magnetic, 287 gm; no.8 copper non-magnetic, 420 gm and 57 cm length. Scale 30 cm on each panel. Rods no.1, no.2 responsive to not widely appreciated. If the forks of resilient wood or metal Ymagnets, rods nos.1, 2, 3, 7, 8 highly conductive (ohmmeter test), rods nos.4, 5, 6 rods are held tightly and squeezed firmly, any relaxation of thenon-magnetic and resistive.clench, through fatigue or whatever, will cause the pointer part to drop, irrespective of the surroundings. Elastic or springy YSo, these simple tests failed completely. For the drum traverses rods can be relied on to give the occasional indication, howeverthe steel divining rod did not exhibit sympathetic interaction meaningless. with the subsurface steel. However, some may say that the rods DECEMBER 2020 PREVIEW 54"