It is carried out by means of a forked twig, hazel by traditional preference, which is grasped in the dowser's two hands and is said to be twisted upwards by an unknown force when there is water underground. As an addition it is sometimes claimed that the twig will indicate the presence of metals by being twisted downwards.
Believers in the twisting of the twig are generally ignorant that it was formerly used in the pursuit and detection of criminals and the finding of buried treasure[7] and that it was being used in the year 1918 to locate a seam of coal. Going farther afield, we learn that the witch-findings practised by African savages are sometimes carried out by means of a stick which points at the victim.
Such varied uses demand a new and complicated system of physics if the results are due to any forces external to the diviner, but my own observations satisfy me that we need not overturn our ordinary conceptions of cause and effect to explain the different properties of the divining-rod.
When a friend told me of the presence of a dowser in the neighbourhood and gave me a would-be convincing account of how he had seen him at work, how the twig was twisted upwards with such force that my informant was unable to depress it, and how the man was employed by engineers to tell them where to sink wells, I became interested and asked to see the marvel. The resulting experiment, though conducted haphazard, was instructive as regards both water-divining and credulity.
The man broke a forked twig from a bush, and, holding it in the way described later, was directed down a path leading to a tennis-court. Along this path no water was known to exist, but the twig rose twice. Beneath the tennis-court ran a water-pipe which had burst during the previous winter, and of which the position was known to six at least of those present. This pipe was located by the man, and he demonstrated it again and again by walking across it, the twig rising each time. It rose again when he was directed past a cook-house. Next he was sent along a path leading from the cook-house to the main building, and the twig rose several times. He said, 'There is water all along here', and was told that there was a pipe running along the path. Here I intervened and asked him to try across one edge of the path, which was about six feet wide. The twig rose, and, just as on the tennis-court, he walked again and again across the indicated line, the twig rising every time, though as a fact the pipe lay on the other side of the path. He explained to us that God gave 'the gift' to Moses, and that now only one man in ten thousand received the gift.
When he left I took a twig and showed that I had the gift, or, at least, that the twig performed in my hands exactly as it had done in his. 'But', said my friends, 'he found the pipe on the tennis-court.' It mattered nothing that he had found water twice within a few yards where none was known, or that at least six of the bystanders knew of the existence of the water-pipe and were ready to show their anticipation as he approached it and their delight when he located it, nor that he located the other pipe on the wrong side of the path. The movements of the twig might be a fraud, his other finds might be failures or guesses, but his one success was enough for them. Even the Padre, when I said that the man had the face typical of a mystic, was moved to ask, 'But may not a mystic have powers of which we know nothing?'
In short, the rising of the twig was produced by the man himself, and his findings were guesses, aided by ordinary knowledge as to where water-pipes are to be expected, and more especially aided by the attitude and expression of the bystanders.
Yet by his manner he showed that he plainly believed in his own powers: otherwise his reference to the gift of God was simple blasphemy, and he seemed an earnest man.