The scene of the Count’s operations was in the valley of the Loire, five leagues from Vendôme, in the park of the Chateau de Ranac. The surface of ground which gave the desired results was from seventy to eighty feet in breadth. But there was another spot equally efficient at the Count’s ordinary residence at Emerillon, near Clery, four leagues south of Orleans, ten leagues south of the Loire, at the commencement of the plains of Solonge. The surface ran from north to south, and had the same breadth with the other. These “exciting tracts” form, in general, bands or zones of undetermined, and often very great length. Their breadth is very variable; some are only three or four feet across, while others are one hundred paces. These tracts are sometimes sinuous; in other instances they ramify. To the most susceptible they are broader than to those who are less so.
M. de Tristan thus describes what happens when a competent person, armed with a hazel-fork, walks over the exciting districts:—
When two or three steps have been made upon the exciting tract of ground, the fork, which at starting is held horizontally, with the point forwards, begins gently to ascend; it gradually attains a vertical position; sometimes it passes beyond that, and lowering itself, with its point to the chest of the operator, it becomes again horizontal. If the motion continues, the rod descending becomes vertical, with the point downwards. Finally, the rod may again ascend and resume its first position. When the action is very lively, the rod immediately commences a second revolution; and so it goes on, as long as the operator continues to walk over the exciting surface of ground.
A few of those in whose hands the divining fork moves exhibit a remarkable peculiarity. The instrument, instead of commencing its motion by ascending, descends; the point then becomes directed vertically downwards; afterwards it reascends, and completes a revolution in a course the opposite of the usual one; and as often and as long as its motion is excited, it pursues this abnormal course.
Of the numerous experiments made by M. de Tristan, the following are among the simplest and the best:—
He covered both handles of a divining rod with a thick silk stuff. The result of using the instrument so prepared was the same which Mr. Fairholm obtained by coating the handles with sealing-wax. The motion of the divining rod was extinguished.