all the land was gold, save one black blot that might have been made by
a single spattered drop of ink, for it was no bigger than the Irish
Island. The persistence of this remaining black on the map of the world
troubled my boyish mind, as it has troubled three generations of the
United World, and strive as I might, I could not comprehend why the
great blackness of the fourth map had been erased and this small blot
alone remained.

~3~

When I returned from school for my vacation, after I had my first year
of physical science, I sought out my uncle in his laboratory and asked
him to explain the mystery of the little black island standing adamant
in the golden sea of all the world.

"That spot," said my uncle, "would have been erased in two more years if
a Leipzig professor had not discovered The Ray. Yet we do not know his
name nor how he made his discovery."

"But just what is The Ray?" I asked.

"We do not know that either, nor how it is made. We only know that it
destroys the oxygen carrying power of living blood. If it were an
emanation from a substance like radium, they could have fired it in
projectiles and so conquered the earth. If it were ether waves like
electricity, we should have been able to have insulated against it, or
they should have been able to project it farther and destroy our
aircraft, but The Ray is not destructive beyond two thousand metres in
the air and hardly that far in the earth."