Nikola Tesla - Free-Energy Devices

882 INVENTIONS OF NIKOLA TESLA.merged in an insulating liquid, it would be safe, for then theenergy would have to spend itself somewhere else. From thebehavior of gases under sudden impulses of high potential, I amled to conclude that there can be no surer way of diverting alightning discharge than by affording it a passage through avolume of gas,if such a thing can be done in a practical manner.There are two more features upon which I think it necessaryto dwell in connection with these experiments the " radiantstate " and the " non-striking vacuum."Anyone who has studied Crookes' work must have receivedthe impression that the " radiant state " is a property of the gasinseparably connected with an extremely high degree of exhaustion.But it should be remembered that the phenomenaobserved in an exhausted vessel are limited to the character andcapacity of the apparatus which is made use of. 1 think that ina bulb a molecule, or atom, does not precisely move in a straightline because it meets no obstacle, but because the velocity impartedto it is sufficient to propel it in a sensibly straight line.The mean free path is one thing, but the velocity the energyassociated with the moving bodyis another, and under ordinarycircumstances I believe that it is a mere question of potential orspeed.A disruptive discharge coil, when the potential ispushedvery far, excites phosphorescence and projects shadows, at comparativelylow degrees of exhaustion. In a lightning discharge,matter moves in straight lines at ordinary pressure when themean free path is exceedingly small, and frequently images ofwires or other metallic objects have been produced by the particlesthrown off in straight lines.I have prepared a bulb to illustrate by an experiment thecorrectness of these assertions. In a globe L, Fig. 160, I havemounted upon a lamp filament f a piece of lime The /.lampfilament is connected with a wire which leads into the bulb, andthe general construction of the latter is as indicated in Fig. 148,before described. The bulb being suspended from a wireconnected to the terminal of the coil, and the latter being set towork, the lime piece I and the projecting parts of the filament fare bombarded. The degree of exhaustion is just such that withthe potential the coil is capable of giving, phosphorescence of theglass is produced, but disappears as soon as the vacuum is impaired.The lime containing moisture, and moisture being givenoff as soon as heating occurs, the phosphorescence lasts only for