Nikola Tesla - Free-Energy Devices

HIGH FREQUENCY AND HIGH POTENTIAL CURRENTS. 249It seems to me quite probable that a similar process takes placein the bulb even with a homogeneous electrode, and I think itto be the principal cause of the disintegration. There is boundto be some irregularity, even if the surface is highly polished,which, of course, is impossible with most of the refractory bodiesemployed as electrodes. Assume that a point of the electrodegets hotter ; instantly most of the discharge passes through thatpoint, and a minute patch it probably fused and evaporated. Itis now possible that in consequence of the violent disintegrationthe spot attacked sinks in temperature, or that a counter force iscreated, as in an arc at ; any rate, the local tearing off meets withthe limitations incident to the experiment, whereupon the sameprocess occurs on another place. To the eye the electrode appearsuniformly brilliant, but there are upon it points constantlyshifting and wandering around, of a temperature far above themean, and this materially hastens the process of deterioration.That some such thing occurs, at least when the electrode is at a lowertemperature, sufficient experimental evidence can be obtained inthe following manner : Exhaust a bulb to a very high degree, sothat with a fairly high potential the discharge cannot pass thatis, not a luminous one, for a weak invisible discharge occursalways, in all probability. Now raise slowly and carefully thepotential, leaving the primary current on no more than for aninstant. At a certain point, two, three, or half a dozen phosphorescentspots will appear on the globe. These places of theglass are evidently more violently bombarded than others, thisbeing due to the unevenly distributed electric density, necessitated,of course, by sharp projections, or, generally speaking, irregularitiesof the electrode. But the luminous patches areconstantly changing in position, which is especially well observableif one manages to produce very few, and this indicates thatthe configuration of the electrode is rapidly changing.From experiences of this kind I am led to infer that, in orderto be most durable, the refractory button in the bulb should bein the form of a sphere with a highly polished surface. Such asmall sphere could be manufactured from a diamond or someother crystal, but a better way would be to fuse, by the employmentof extreme degrees of temperature, some oxide as, foinstance, zirconia into a small drop, and then itkeep in thebulb at a temperature somewhat below its point of fusion.Interesting and useful results can, no doubt, be reached in the