Some writers have even produced entire treatises on the ruses of these monks. Among the stratagems cited is the illusion of turning water into oil: they keep the oil hidden inside a hollow pillar, and whenever the level drops they pour water into it. The oil then rises to the surface and the onlookers imagine that the very water has been transformed into oil.

Another trick relates to the “ascending palm-tree.” A traveler once passed by a monk’s monastery that stood above a palm tree. The monk showed him the tree rising, little by little, until it reached the level of the monastery; the visitor picked some fresh dates, after which the tree descended and returned to its original place. The traveler uncovered the deception and found the palm tree set in a boat situated in a low-lying spot. When water was let in, the low-lying space filled and the boat rose; when the water was diverted elsewhere, the boat sank back down.

A third ploy concerns the so-called “kohl made from the Lady’s tears.” They place powdered kohl in gently swirling water until it dissolves and flows down from the icon, emerging from the figure’s eye so that people think it is weeping.

Still another example is the trick they perform with the image they call al-quna