for the flood
of light which poured from the mountains. Sir William Herschel 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 hypotheses 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 an air line was
something over 300 miles. Our course lay across the north-eastern 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 Apennines, 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.

A Gigantic String Of Diamonds.

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
device, practiced by all climbers of lofty mountains, where the glare
of sunlight upon 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.

A Mountain of Crystals.

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 bro