By such raps these operators convey considerable information regarding the mechanisms by which the phenomena are produced—believe it or not as you please.
At this point it is rght to state that the author in the previous volume above mentioned has dealt with the reality of these psychic phenomena and has satisfied himself not only of their veridity, but of the actuality of his friends the "invisible operators." He therefore in the present volume quite logically assumes that this aspect of the problem has been proved and there is no longer need of eliminating or testing for conscious or unconscious fraud on the part of the medium or the six sitters, or of the invisible operators. It is only fair to bear this conviction in mind in reading his fascinating exposition.
Now what is the author's hypothesis regarding the mechanism by which the levitation is accomplished? By the invisible operators boldly grasping the table and manipulating it, like an invisible juggler? Not at all. Nothing so commonplace as that. He conceives of a "psychic" rod, sometimes several rods, projected from the body of the medium—sometimes (apparently) from the stomach, sometimes from the ankles according to the exigencies of the phenomena. The operators testify to the existence of these rods and actually describe their size and shape. When, for instance, the table is levitated in the normal way the psychic rod projecting from the stomach acts as a cantilever, that is a rod which has a fixed end or support in the body of the medium and a free end which is applied to the table. The rod is rigid. It is a form of matter. It has weight. (Mr. Crawford has actually weighed it and found it may weigh as much as 50 lbs!) And yet it is impalpable and invisible. You can pass your hand through and across it and feel nothing. It is matter which is "driven out of the medium's body." "The method by which it is expelled is a mystery" but, apparently, the operators extract it. Here, then, is a form of matter with which, as Mr. Crawford frankly states, science is unacquainted.
The rapping rods are somewhat different in form and size—at least so the invisible ones say. They too issue from and are fixed to the body, but are semi-flexible and considerably smaller than the cantilever, being about 2 inches in diameter. The invisibles, presumably grasping the rod, strike the floor or table with it, producing light little taps or ponderous sledge-hammer blob's.
Queer kind of matter this that is projected and so manipulated! It is obvious that if a rigid bar were firmly fixed by one end in the medium's body and if a weight were applied to the other free end of the bar, the weight of the medium's body would be increased by the amount of the added weight.
If on the other hand, the rigid bar were bent upwards at approximately a right angle at about the middle or near the end, and at the bend it rested upon the floor, or upon a spring pressing upwards, the increased weight would be taken up by the resisting floor, or spring, and, in the latter case, the medium's body would decrease if the upward pressure of the spring were greater than that of the