a. So to dispose the apparatus employed that the movement to be produced shall be one that the mechanical action of the fingers could not compass.
b. To set up movements at a distance without any kind of contact.
The following were our first experiments:
A. Mechanical action rendered impossible. The first experiment attempted along this line gave wholly negative results. We suspended a table by a cord that passed over two pulleys fixed in the ceiling and had a counter-weight attached to the free end. It was easy, by regulating this counterpoise, to balance in the air either the total weight of the table or only a fraction, more or less great, thereof.
As a matter of fact, the table hung almost in equilibrium with the weight, one only of its three legs touching the floor. The operators placed their hands upon the top surface. We acted at first in a circular direction, a disposition of the force the efficacy of which had been established by previous experiments. We then tried in vain to lift the table by detaching it from the floor. No positive result was obtained.
We had already (during the previous year) had a table suspended to a dynamometer, and the efforts of four mesmerizers were powerless to relieve the dynamometer of an appreciable fraction of the weight of the table.
But the conditions necessary for the production of the phenomena were still unknown to us, and, consequently, when the experiments tried led to negative results, we had to try others, without pressing too hastily for inferences and conclusions. It was thus that we secured the results which I am going to describe.
Experiment with the Swinging Table.—We needed a piece of apparatus of such a kind that the mechanical action of the fingers would be rendered impossible. For this purpose we had a table made with a top about 33 inches in diameter, and a central trifurcated leg underneath. This table bore a close resemblance to the one which had served our purposes up to that time, and could turn like its predecessor. Still, the new table was capable of being transformed in a moment into a mechanism such as I shall now describe.
The summit of the tripod becomes the fulcrum of a lever of the first order which is able to balance freely in a vertical plane. This lever, whose two arms are equal to each other and to the radius of the table bears at one of its extremities the table-top, held by the edge, and, toward the other extremity, a counterpoise which just balances the weight of the table, but which can be modified at will. To the under side of the table-top is fastened a leg resting on the floor.
After the necessary preliminary rotations, the table is harnessed up in its second form. Equilibrium is first secured, then 3-5 of a pound is taken from the counterpoise. The force required to lift the top by its centre is then 4 ounces, and previous experiments have proved that the adherence of the fingers of the operators (the top was polished, and not varnished), together with the possible effects of elasticity, form a total lower than that figure. Yet the top is lifted by the action of the fingers placed lightly on its upper surface, at a certain distance from the edge. Then the counterpoise is diminished; the mechanical difficulty of lifting is augmented, yet still it takes place. The weight is again diminished, and more and more, up to the limit of the apparatus. The force necessary to lift the top is then 8 1-5 pounds, and the counterpoise has been relieved of 24 pounds; yet the levitation is easily accomplished. The number of the operators is gradually lessened from eleven to six. The difficulty goes on increasing, yet six operators still suffice; but five are not enough. Six operators lift 9 1-3 pounds,—an average for each man of about 1½ pounds.