Nikola Tesla - Free-Energy Devices

248 INVENTIONS OF NIKOLA TE8LA.to be rendered incandescent. Fig. 153 (page 263) illustrates oneof the bulbs used. It consists of a spherical globe L, providedwith a long neck n, on top, for increasing the action in some casesby the application of an external conducting coating. The globe Lis blown out on the bottom into a very small bulb Z>,which servesto hold it firmly in a socket s of insulating material into which itis cemented. A fine lamp filament f, supported on a wire w,passes through the centre of the globe L. The filament is renderedincandescent in the middle portion, where the bombardmentproceeding from the lower inside surface of the globe ismost intense. The lower portion of the globe, as far as thesocket s reaches, is rendered conducting, either by a tinfoil coatingor otherwise, and the external electrode is connected to aterminal of the coil.The arrangement diagrammatically indicated in Fig. 153 wasfound to be an inferior one when it was desired to render incandescenta filament or button supported in the centre of the globe,but it was convenient when the object was to excite phosphorescence.In many experiments in which bodies of different kind weremounted in the bulb as, for instance, indicated in Fig. 152, someobservations of interest were made.It was found, among other things, that in such cases, no matterwhere the bombardment began, just as soon as a high temperaturewas reached there was generally one of the bodieswhich seemed to take most of the bombardment upon itself, theother, or others, being thereby relieved. The quality appearedto depend principally on the point of fusion, and on the facilitywith which the body was " evaporated," or, generally speaking,disintegrated meaning by the latter term not only the throwingoff of atoms, but likewise of large lumps. The observation madewas in accordance with generally accepted notions. In a highlyexhausted bulb, electricityis carried off from the electrode byindependent carriers, which are partly the atoms, or molecules,of the residual atmosphere, and partly the atoms, molecules, orlumps thrown off from the electrode. If the electrode is composedof bodies of different character, and if one of these is moreeasily disentegrated than the other, most of the electricity suppliedis carried off from that body, which is then brought to ahigher temperature than the others, and this the more, as uponan increase of the temperature the bodyis still more easily disintregrated.