dependent on the potential of the impulses and
on the electric density on the surface of the electrode. In employing
very high frequencies the loss of energy by the bombardment is greatly
reduced, for, first, the potential needed to perform a given amount of
work is much smaller; and, secondly, by producing a highly conducting
photosphere around the electrode, the same result is obtained as
though the electrode were much larger, which is equivalent to a
smaller electric density. But be it by the diminution of the maximum
potential or of the density, the gain is effected in the same manner,
namely, by avoiding violent shocks, which strain the glass much beyond
its limit of elasticity. If the frequency could be brought high
enough, the loss due to the imperfect elasticity of the glass would be
entirely negligible. The loss due to bombardment of the globe may,
however, be reduced by using two electrodes instead of one. In such
case each of the electrodes may be connected to one of the terminals;
or else, if it is preferable to use only one wire, one electrode may
be connected to one terminal and the other to the ground or to an
insulated body of some surface, as, for instance, a shade on the lamp.
In the latter case, unless some judgment is used, one of the
electrodes might glow more intensely than the other.

But on the whole I find it preferable when using such high frequencies
to employ only one electrode and one connecting wire. I am convinced
that the illuminating device of the near future will not require for
its operation more than one lead, and, at any rate, it will have no
leading-in wire, since the energy required can be as well transmitted
through the glass. In experimental bulbs the leading-in wire is most
generally used on account of convenience, as in employing condenser
coatings in the manner indicated in Fig. 22, for example, there is
some difficulty in fitting the parts, but these difficulties would not
exist if a great many bulbs were manufactured; otherwise the energy
can be conveyed through the glass as well as through a wire, and with
these high frequencies the losses are very small. Such illuminating
devices will necessarily involve the use of very high potentials, and
this, in the eyes of practical men, might be an objectionable feature.
Yet, in reality, high potentials are not objectionable--certainly not
in the least as far as the safety of the devices is concerned.

There are two ways of renderi