Here the author has a short, but particularly interesting account to tell of the time he watched an Indian water diviner at work. But it is water divining in the most extraordinary manner.

“Water-divining in Malabar” by M. K. Krishnaswami, M.A.

http://www.dowsing-research.net/blog_extracts/BSD_No10_1935_p125.pdf

As the author points out, in England at this time, the forked stick was perhaps the most common divining device for outdoors work and he comments how forcibly the rod could move for some diviners, “… the intensity of the “spin” is so great that a strong man cannot keep the twig moving; occasionally it flies clean out of the “dowser’s “ hands.” This is suggestive of an additional force at work, beyond that of the dowser tensing the rod to put it into a state of unstable equilibrium. There are other accounts in the BSD journals too, in which extraordinary forces appear to be operating for certain dowsers, and this might be evidence for a macro-psychokinesis (PK). If this explanation seems too incredible, then read the account of how the Indian diviner worked. Taken at face value, this is an extraordinary example of PK at work.

Dowsing has a host of practical applications. One profession which has often embraced it is that of Civil Engineering. Presumably Civil Engineers are practical people and if any method is found to get the necessary results in an efficient manner, then they will adopt it. This was particularly so in the age before reliable underground surveying instruments became widely available.

Here is one application from the 1940s. In which the Engineer used dowsing to successfully locate the position of a leak in a reservoir, a finding later verified by visual inspection.

“Water divining and its relation to civil engineering”, by I. Hopkins.

http://www.dowsing-research.net/blog_extracts/BSD_No28_1940_p128.pdf

Being an Engineer, he puts forward some ideas, current at the tie, as to the mechanism behind dowsing. But also concludes that there was a definite role for the subconscious mind.   

Here is a very short, but interesting letter to the BSD from Mr John Browne.

http://www.dowsing-research.net/blog_extracts/BSD_No265_1999_p331.pdf

It contains a survey of the pendulum responses of nine dowsers. For those unaccustomed to the use of the pendulum in dowsing, there are typically three actions it will demonstrate. The first is the neutral response, when the dower is posing the question. In many accounts that aim to teach how to use the pendulum, it is suggested to let it swing to and fro along a line. In response to the question, the pendulum will give either a yes or no response. Again, it is commonly suggested, when learning to use the device, to specify two differing movements that can be easily distinguished. For instance, gyration to the left, or to the right are often suggested, the operator being free to assign meanings to either. In addition to the three basic movements, there can also be a fourth action, distinguishable from the others, here it is referred to as the idiot response, because it occurs when the question is not well posed, and neither a yes, or no answer is appropriate. 

In the table, it is interesting to observe that each of the dowsers exhibits a unique set of the four responses, with no two dowsers having the same set. Perhaps another interesting observation is that for some, the neutral position is a stationary pendulum, but none of the remaining three actions has this stationary signature, ie the response to the questioning is always an active one.

As alluded to above, when setting out, the novice dowser may specify the meaning of the pendulum’s movement, or alternatively they might just accept any movement the pendulum exhibits to their request to demonstrate the response to the four situations.  Given the personal nature of the reaction, it seems again that the dowsing reaction is mediated by (unconscious) mental processes, which as has been commented on previously, is subject to a type of mental programming.