This post concerns a short note taken in translation from the French dowsing journal, La Radiesthesie Pour Tous (L.R.P.T.) of December 1936, page 335 (now sadly a publication no more). It appears that the dowser was using her pendulum with something simiar to a Ouija board. It is a dowsing practice which I have not found reference to previously, at least in the BSD journals. Here is the summary of the account (tanslated from the original French).
“Last year some Canadian readers visited the L.R.P.T. office, among whom was a Mme. Sergerie. This lady demonstrated a semi-circular diagram in which letters and figures are inscribed. It is claimed that answers to any questions can be obtained with the help of the pendulum from this diagram, providing that the operator has the necessary aptitude …. Some operators find it better to orientate the diagram before using it, but for others this is not necessary. ” [the original article contained a reproduction of the figure].