difficult on account of the fundamental vibration.
The demonstration of the fact--which still needs better experimental
confirmation--that a vibrating gaseous column possesses rigidity,
might greatly modify the views of thinkers. When with low frequencies
and insignificant potentials indications of that property may be
noted, how must a gaseous medium behave under the influence of
enormous electrostatic stresses which may be active in the
interstellar space, and which may alternate with inconceivable
rapidity? The existence of such an electrostatic, rhythmically
throbbing force--of a vibrating electrostatic field--would show a
possible way how solids might have formed from the ultra-gaseous
uterus, and how transverse and all kinds of vibrations may be
transmitted through a gaseous medium filling all space. Then, ether
might be a true fluid, devoid of rigidity, and at rest, it being
merely necessary as a connecting link to enable interaction. What
determines the rigidity of a body? It must be the speed and the amount
of moving matter. In a gas the speed may be considerable, but the
density is exceedingly small; in a liquid the speed would be likely to
be small, though the density may be considerable; and in both cases
the inertia resistance offered to displacement is practically _nil_.
But place a gaseous (or liquid) column in an intense, rapidly
alternating electrostatic field, set the particles vibrating with
enormous speeds, then the inertia resistance asserts itself. A body
might move with more or less freedom through the vibrating mass, but
as a whole it would be rigid.
There is a subject which I must mention in connection with these
experiments: it is that of high vacua. This is a subject the study of
which is not only interesting, but useful, for it may lead to results
of great practical importance. In commercial apparatus, such as
incandescent lamps, operated from ordinary systems of distribution, a
much higher vacuum than obtained at present would not secure a very
great advantage. In such a case the work is performed on the filament
and the gas is little concerned; the improvement, therefore, would be
but trifling. But when we begin to use very high frequencies and
potentials, the action of the gas becomes all important, and the
degree of exhaustion materially modifies the results. As long as
ordinary coils, even very large ones, were used, the study of the
subject was limited, because just at a point when it became most
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