b"Divination: A geophysicist's viewFeatureFigure 11. Don the Dowser with steel rod no.1 (Figure 10) fruitlessly searches for 50 L steel drums buried at shallow depth in area B previously geophysically and successfully surveyed with magnetics, TEM, and resistivity. This method of divination failed to locate the drums. The forked steel rod neither twitched nor dipped (except by clench-fatigue).are fine, but that deficiencies in my qualities are responsible, in that I do not have the gift. I could only concur with this. Doubtless I would have failed in the type of trial depicted by the English artist Heath Robinson in his 1924 cartoon on testing candidates for the position of water diviner on the Metropolitan Water Board (Figure 12).PhysicsCan the divining rod respond to potential fields? Is gravity theFigure 12.Testing of candidates for the position of water diviner on theforce to which a rod is sensitive? It would seem highly unlikelyMetropolitan Water Board: a 1924 cartoon by the comic visionary Heath if not impossible that a rod could be calibrated to registerRobinson (1872-1944) who excelled in portraying gentle eccentricities, absolute gravity (even in pendulum divining instruments,makeshift contraptions, and the debunking of officials and individuals who not discussed here). What about relative gravity? Geophysicstook themselves too seriously. His hazel twigs, presumably possessing a peculiar polarity, move up to strike a bell detector to indicate a successful detection procedures require instrumental drift, earth tide, elevation,of water underneath. Public domain / https://commons.wikimedia.org/wiki/latitude, Bouguer, and, sometimes, terrain corrections.File:William_Heath_Robinson_Inventions_-_Page_055.png. From the book Anomalous gravity affects are acceleration differences and areWilliam Heath Robinson Inventions.expressed in gravity units (g.u. ms 2, 0.1 milligal) which are tiny accelerations about 10 7 that of normal gravity. Most anomaliesNow the force between the rod (m 1 ) and the junk (m 2 ) is range from a few to a few hundred g.u. Gravity studies requireobtained from:highly sensitive instruments and rigorous field procedures. This is really not a descriptor of divining where a rod is carried atF=G m 1 m 2inconstant height by a quivering human frame. r 2Does gravity yank a rod down or sideways? Consider a 100 gAnd F in this case is 6.67 x 10 9 N. A force of the order of rod very near the earths surface and 1 t of compact junk justnanonewtons is insignificant compared to the previous forces, below the earths surface and 1m away on a transverse line. Weand quite unable to cause the rod to move.acknowledge the earths gravity which acts on both (assuming them to be quasi spherical with mass concentrated at theIf gravity cannot explain the physics of the divining rod can centre) pursuant to the Newtons inverse square law: magnetics do so if the necessary changes are made to the inverse power-of-distance equation? Considerations would be F=G Mm limited to only two of the rods, the magnetically responsive no. r 2 1 and no. 2. However, assuming some sort of magnetised target, 11 2 2 the situation is worse than gravity given the approximate1 fall G=6.6710newton m kg , gravitational constant r 3M = mass of earth, 5.981024 kg off of the magnetic field from the target body.m = mass of surface object For the conductive rods (nos. 1, 2, 3, 7, 8) there is another r = radius of earth, 6.38106 m aspect of magnetics that can be considered. This does not involve rod twisting, but rod charging which the dowser may for the divining rod (m = 0.1 kg) the earths force is about 1sense. A conductive rod in motion in a magnetic field will Newton (similar to the force of a falling apple), and for the junkundergo electrical polarisation as shown in Figure 13. The (m = 1000 kg) the force is about 10 000 Newtons (alternativelyvoltage difference between the ends is the product of the weights, w, could be computed from w = mg where w is infield magnitude, the rod length, and the rod velocity i.e. Blv. Newtons and g is the acceleration of gravity 9.8 ms 2). Imagine a dowser traversing with a horizontally held copper 55 PREVIEW DECEMBER 2020"