Nikola Tesla - Free-Energy Devices

HIGH FREQUENCY AND HIGH POTENTIAL CURRENTS. 187ous by interposing an insulated metal plate. The magnitude ofthe effects depends to some extent on the size of the plate. But ifthe metal plate be connected'by a wire to the ground, its interpositionwill always make the tube go out even if it be very near thecoil. In general, the interposition of a body between the coil andtube, increases or diminishes the brilliancy of the tube, or itsfacility to light up, according to whether it increases or diminishesthe electrification. When experimenting with an insulatedplate, the plate should not be taken too large, else it will generallyproduce a weakening effect by reason of its great facility for givingoff energy to the surroundings.If a tube be lighted at some distance from the coil, and a plateof hard rubber or other insulating substance be interposed, thetube may be made to go out. The interposition of the dielectricin this case only slightly increases the inductive effect, but diminishesconsiderably the electrification through the air.In all cases, then, when we excite luminosity in exhaustedtubes by means of such a coil, the effect is due to the rapidlyalternating electrostatic potential ; and, furthermore, it must beattributed to the harmonic alternation produced directly by themachine, and not to any superimposed vibration which might bethought to exist. Such superimposed vibrations are impossiblewhen we work with an alternate current machine. If a spring begradually tightened and released, it does not perform independentvibrations ;for this a sudden release is necessary. So withthe alternate currents from a dynamo machine ;the medium isharmonically strained and released, this giving rise to only onekind of waves ;a sudden contact or break, or a sudden givingway of the dielectric, as in the disruptive discharge of a Leydenjar, are essential for the production of superimposed waves.In all the last described experiments, tubes devoid of any electrodesmay be used, and there is no difficulty in producing bytheir means sufficient light to read by. The light effect is,however,considerably increased by the use of phosphorescent bodiessuch as yttria, uranium glass,etc. A difficultywill be foundwhen the phosphorescent material is used, for with these powerfuleffects, it is carried gradually away, and it is preferable to usematerial in the form of a solid.Instead of depending on induction at a distance to light thetube, the same may be provided with an external and, if desired,also with an internal condenser coating, and it may then