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