f the divining rod seems to have been
restricted to the search for metals. The first (or one of the first)
to raise his voice against it was the learned G. Agricola[102]
(1556), and after him there were many who all wrote more or less
independently of one another. Aside from swindle and chance, it was
usually believed that sorcery of the agency of Beelzebub was
involved, and for that reason the Church has repeatedly forbidden
the use of the divining-rod. But even in the 17th century we find
some who believed that it was imagination alone that moved the
person's hand, and with it the rod,[103, 104] ("fortassis etiam
phantasia manum in motum concitante"); and that points out the
essentials of the solution of the phenomenon, and we will not go
into the matter here in detail. A number of complex psychological
problems arising in connection with it are still waiting to be
solved, but this much appears certain; the staff or branch plays no
other part in the whole process than that which is served by the
three levers in the tests described in Chapter IV (pages 116
ff.),--they simply magnify the expressive movements of the diviner.
And so we can understand why the instruments serving as rod might be
so varied. Hay-forks, pickets, clock-springs and pendulums, scissors
and pliers have been used. A knife and fork or two pipes, fastened
together, an open book, and even a sausage, grasped at both ends and
thus bent together somewhat,--all have served the purpose equally
well. We can understand, too, how some adepts are able to achieve
the same degree of success--for they do succeed beyond a
doubt--without any rod whatever, but simply by placing the index
fingers end to end and bending them somewhat, and even by merely
groping about with hands outstretched or folded before them.[106]]

Two other phenomena may have tended to strengthen Mr. von Osten's belief
in Hans's intelligence. One was the misleading similarity with which the
horse's supposed errors in computation and the poorly adjusted
concentration of the questioner, were expressed. We recall the
difficulty in the case of very high numbers. This might easily be
considered as being due to the horse's ability to work more readily with
small, rather than with large numbers, whereas, as a matter of fact, it
was due solely to the difficulty of the questioner to keep his attenti