Loosely wound helixes of copper wire, with no insulation, and of large diameter, gave best results. The number of turns in a coil did not seem to be as large an influence as other factors. In fact, a single wire loop, or a bare strip of copper worked, though poorly. The polarity effect noticed in the first experiment was observable only with coils. With single loops or metal strips, the polarity seemed almost random.
Coils wound on an iron core gave no indication at all.
Coils wound on plastic or paper gave slight current indications. Coils with no core or coil form gave best indications. Wire insulation, in all cases, seemed to interfere with the production of the current. Different ORACs were tried. Flipping ORACs on their sides, or placing them upside down did not seem to make any difference.