The First Men in the Moon | Page 8

some blunder that
would bring upon me the mockery of every up-to-date student of
mathematical physics in the country. The best thing I can do therefore
is, I think to give my impressions in my own inexact language, without
any attempt to wear a garment of knowledge to which I have no claim.

The object of Mr. Cavor's search was a substance that should be
"opaque " - he used some other word I have forgotten, but "opaque"
conveys the idea - to "all forms of radiant energy." "Radiant energy,"
he made me understand, was anything like light or heat, or those
Rontgen Rays there was so much talk about a year or so ago, or the
electric waves of Marconi, or gravitation. All these things, he said,
radiate out from centres, and act on bodies at a distance, whence comes
the term "radiant energy." Now almost all substances are opaque to
some form or other of radiant energy. Glass, for example, is transparent
to light, but much less so to heat, so that it is useful as a fire-screen; and
alum is transparent to light, but blocks heat completely. A solution of
iodine in carbon bisulphide, on the other hand, completely blocks light,
but is quite transparent to heat. It will hide a fire from you, but permit
all its warmth to reach you. Metals are not only opaque to light and
heat, but also to electrical energy, which passes through both iodine
solution and glass almost as though they were not interposed. And so
on.
Now all known substances are "transparent" to gravitation. You can use
screens of various sorts to cut off the light or heat, or electrical
influence of the sun, or the warmth of the earth from anything; you can
screen things by sheets of metal from Marconi's rays, but nothing will
cut off the gravitational attraction of the sun or the gravitational
attraction of the earth. Yet why there should be nothing is hard to say.
Cavor did not see why such a substance should not exist, and certainly I
could not tell him. I had never thought of such a possibility before. He
showed me by calculations on paper, which Lord Kelvin, no doubt, or
Professor Lodge, or Professor Karl Pearson, or any of those great
scientific people might have understood, but which simply reduced me
to a hopeless muddle, that not only was such a substance possible, but
that it must satisfy certain conditions. It was an amazing piece of
reasoning. Much as it amazed and exercised me at the time, it would be
impossible to reproduce it here. "Yes," I said to it all, "yes; go on!"
Suffice it for this story that he believed he might be able to
manufacture this possible substance opaque to gravitation out of a
complicated alloy of metals and something new - a new element, I
fancy - called, I believe, helium, which was sent to him from London in

sealed stone jars. Doubt has been thrown upon this detail, but I am
almost certain it was helium he had sent him in sealed stone jars. It was
certainly something very gaseous and thin. If only I had taken notes...
But then, how was I to foresee the necessity of taking notes ?
Any one with the merest germ of an imagination will understand the
extraordinary possibilities of such a substance, and will sympathise a
little with the emotion I felt as this understanding emerged from the
haze of abstruse phrases in which Cavor expressed himself. Comic
relief in a play indeed! It was some time before I would believe that I
had interpreted him aright, and I was very careful not to ask questions
that would have enabled him to gauge the profundity of
misunderstanding into which he dropped his daily exposition. But no
one reading the story of it here will sympathise fully, because from my
barren narrative it will be impossible to gather the strength of my
conviction that this astonishing substance was positively going to be
made.
I do not recall that I gave my play an hour's consecutive work at any
time after my visit to his house. My imagination had other things to do.
There seemed no limit to the possibilities of the stuff; whichever way I
tried I came on miracles and revolutions. For example, if one wanted to
lift a weight, however enormous, one had only to get a sheet of this
substance beneath it, and one might lift it with a straw My first natural
impulse was to apply this principle to guns and ironclads, and all the
material and methods of war, and from that to shipping, locomotion,
building, every conceivable form of human industry. The chance that
had brought me into the very birth-chamber of this