the fantastic inventions of nikola tesla - Exopolitics Hong Kong

doubt that to such small disturbance as might be caused in an experiment the earth behaves as an almost perfect
condenser. But it might be different when its charge is set in vibration by some sudden disturbance occurring in the
heavens. In such case, as before stated, probably only little of the energy of the vibrations set up would be lost into
space in the form of long ether radiations, but most of the energy, I think, would spend itself in molecular impacts
and collisions, and pass off into space in the form of short heat, and possibly light, waves. As both the frequency of
the vibrations of the charge and the potential are in all probability excessive, the energy converted into heat may be
considerable. Since the density must be unevenly distributed, either in consequence of the irregularity of the earth's
surface, or on account of the condition of the atmosphere in various places, the effect produced would accordingly
vary from place to place. Considerable variations in the temperature and pressure of the atmosphere may in this
manner be caused at any point of the surface of the earth. The variations may be gradual or very sudden, according
to the nature of the general disturbance, and may produce rain and storms, or locally modify the weather in any
way. From the remarks before made one may see what an important factor of loss the air in the neighborhood of a
charged surface becomes when the electric density is great and the frequency of the impulses excessive. But the
action as explained implies that the air is insulating—that is that it is composed of independent carriers immersed in
an insulating medium. This is the case only when the air is at something like ordinary or greater, or at extremely
small, pressure. When the air is slightly rarefied and con ducting, then true conduction losses occur also. In such
case, of course, considerable energy may be dissipated into space even with a steady potential, or with impulses of
low frequency, if the density is very great.
When the gas is at very low pressure, an electrode is heated more because higher speeds can be reached. If the gas
around the electrode is strongly compressed, the displacements, and consequently the speeds, are very small, and
the heating is insignificant. But if in such case the frequency could be sufficiently increased, the electrode would be
brought to a high temperature as well as if the gas were at very low pressure; in fact, exhausting the bulb is only
necessary because we cannot produce (and possibly not convey) currents of the required frequency.
Returning to the subject of electrode lamps, it is obviously of advantage in such a lamp to confine as much as
possible the heat to the electrode by preventing the circulation of the gas in the bulb. If a very small bulb be taken,
it would confine the heat better than a large one, but it might not be of sufficient capacity to be operated from the
coil, or, if so, the glass might get too hot. A simple way to improve in this direction is to employ a globe of the
required size, but to place a small bulb, the diameter of which is properly estimated, over the refractory button
contained in the globe. This arrangement is illustrated in Fig. 28. The globe L has in this case a large neck n,
allowing the small bulb b to slip through. Otherwise the construction is the same as shown in Fig. 18, for example.
The small bulb is conveniently supported upon the stem s, carrying the refractory button m. It is separated from the
aluminium tube a by several layers of mica M, in order to prevent the cracking of the neck by the rapid heating c f
the aluminium tube upon a sudden turning on of the current. The inside bulb should be as small as possible when it
is desired to obtain light only by incandescence of the electrode. If it is desired to produce phosphorescence, the
bulb should be larger, else it would be apt to get too hot, and the phosphorescence would cease. In this arrangement
usually only the small bulb shows phosphorescence, as there is practically no bombardment against the outer globe.
In some of these bulbs constructed as illustrated in Fig. 28 the small tube was coated with phosphorescent paint,
and beautiful effects were obtained. Instead of making the inside bulb large, in order to avoid undue heating, it
answers the purpose to make the electrode m larger. In this case the bombardment is weakened by reason of the
smaller electric density.
Many bulbs were constructed on the plan illustrated in Fig. 29. Here a small bulb b, containing the refractory button
m, upon being exhausted to a very high degree was sealed in a large globe L, which was then moderately exhausted
and sealed off. The principal advantage of this construction was that it allowed of reaching extremely high vacuum,
and, at the same time use a large bulb. It was found, m the course of experiences with bulbs such as illustrated in
Fig. 29, that it was well to make the stem s near the seal at e very thick, and the leading-in wire w thin, as it occurred
sometimes that the stem at e was heated and the bulb was cracked. Often the outer globe L was exhausted
only just enough to allow the discharge to pass through and the space between the bulbs appeared crimson,
producing a curious effect. In some cases, when the exhaustion in globe L was very low, and the air good
conducting it was found necessary, in order to bring the button m to high incandescence, to place, preferably on the
upper part of the neck of the globe, a tinfoil coating which was connected to an insulated body, to the ground, or to
the other terminal of the coil, as the highly conducting air weakened the effect somewhat, probably by being acted
upon inductively from the wire w, where it entered the bulb at e. Another difficulty—which, however, is always
present when the refractory button is mounted in a very small bulb existed in the construction illustrated in Fig. 29,
namely, the vacuum in the bulb b would be impaired in a comparatively short time.