shel had been so
completely misled by this appearance that he supposed he was watching a
lunar volcano in eruption.

It had always been a difficult question what caused the extraordinary
luminosity of Aristarchus. No end of hypothesis had been invented to
account for it. Now I was to assist in settling these questions forever.

From Cape Heraclides to Aristarchus the distance in air line was
something over 300 miles. Our course lay across the northeastern part of
the Sea of Showers, with enormous cliffs, mountain masses and peaks
shining on the right, while in the other direction the view was bounded
by the distant range of the lunar Appenines, some of whose towering
peaks, when viewed from our immense elevation, appeared as sharp as the
Swiss Matterhorn.

When we had arrived within about a hundred miles of our destination we
found ourselves, floating directly over the so-called Harbinger
Mountains. The serrated peaks of Aristarchus then appeared ahead of us,
fairly blazing in the sunshine.

It seemed as if a gigantic string of diamonds, every one as great as a
mountain peak, had been cast down upon the barren surface of the moon
and left to waste their brilliance upon the desert air of this abandoned
world.

As we rapidly approached the dazzling splendor of the mountain became
almost unbearable to our eyes, and we were compelled to resort to the
devise, practised by all climbers of lofty mountains, where the glare of
sunlight on snow surfaces is liable to cause temporary blindness, of
protecting our eyes with neutral-tinted glasses.

Professor Moissan, the great French chemist and maker of artificial
diamonds, fairly danced with delight.

"Voila! Voila! Voila!" was all that he could say.

When we were comparatively near, the mountain no longer seemed to glow
with a uniform radiance, evenly distributed over its entire surface, but
now innumerable points of light, all as bright as so many little suns,
blazed away at us. It was evident that we had before us a mountain
composed of, or at least covered with, crystals.

Without stopping to alight on the outer slopes of the great ring-shaped
range of peaks which composed Aristarchus, we sailed over their rim and
looked down into the interior. Here the splendor of the crystals was
greater than on the outer slopes, and the broad floor of the crater,
thousands of feet beneath us, shone and sparkled with overwhelming
radiance, as if it were an immense bin of diamonds,