Endless Cord, Tying Knots in
Around 187778 J. C. F. Zöllner (18341882) of Leipzig,
Germany, investigated the phenomena of the medium Henry
Slade, looking particularly for anything that might prove a
fourth dimension of space, a hypothesis in which Zöllner was
greatly interested.
Tying in an endless cord such knots as could ordinarily only
be made if the ends of the cord were free was to provide such
a test. In December 1877 Zöllner visited Slade with two pieces
of hempen cord, the free ends of each being sealed to a piece
of cardboard. To ensure that the cord was always in sight, Zöllner
hung it round his neck, and kept Slades hands continually
in view. Under these circumstances four knots were produced,
apparently on the original sealed cord. This experiment was in
no way conclusive in the light of Slades later reputation as a
fraud and in view of the startling tricks performed by stage magicians
with cords and rings. Zöllner reported on his experiment
in his book Transcendental Physics (1880), which became
the object of much ridicule by his colleagues.