we're approaching it from the central
sun, and almost in line with their own sun, so it's daylight all over
it. As it turns and as we get closer, we'll see what we can see. Better
take turns watching it, hadn't we?" asked Seaton.

It was decided, and while the _Skylark_ was still some distance away,
several small islands became visible, and the period of rotation of the
planet was determined to be in the neighborhood of fifty hours.
Margaret, then at the controls, picked out the largest island visible
and directed the bar toward it. As they dropped down close to their
objective, they found that the air was of the same composition as that
of Osnome, but had a pressure of seventy-eight centimeters of mercury,
and that the surface gravity of the planet was ninety-five hundredths
that of the Earth.

"Fine business!" exulted Seaton. "Just about like home, but I don't see
much of any place to land without getting wet, do you? Those reflectors
are probably solar generators, and they cover the whole island except
for that lagoon right under us."

The island, perhaps ten miles long and half that in width, was entirely
covered with great parabolic reflectors, arranged so closely together
that little could be seen between them. Each reflector apparently
focussed upon an object in the center, a helix which seemed to writhe
luridly in that flaming focus, glowing with a nacreous, opalescent green
light.

"Well, nothing much to see there--let's go down," remarked Seaton as he
shot the _Skylark_ over to the edge of the island and down to the
surface of the water. But here again nothing was to be seen of the land
itself. The wall was one vertical plate of seamless metal, supporting
huge metal guides, between which floated metal pontoons. From these
gigantic floats metal girders and trusses went through slots in the wall
into the darkness of the interior. Close scrutiny revealed that the
large floats were rising steadily, although very slowly; while smaller
floats bobbed up and down upon each passing wave.

"Solar generators, tide-motors, and wave-motors, all at once!"
ejaculated Seaton. "_Some_ power-plant! Folks, I'm going to take a look
at that if I have to drill in with a ray!"

[Illustration: Some power plant! Folks, I'm going to take a look at
that....]

They circumnavigated the island without revealing any door or other
opening--the entire thirty miles was one stupendous battery of the
generators. Back at the starting po