But the projectile was now describing in the shadow that
incalculable course which no sight-mark would allow them
to ascertain. Had its direction been altered, either by the
influence of the lunar attraction, or by the action of some
unknown star? Barbicane could not say. But a change had taken
place in the relative position of the vehicle; and Barbicane
verified it about four in the morning.

The change consisted in this, that the base of the projectile
had turned toward the moon's surface, and was so held by a
perpendicular passing through its axis. The attraction, that is
to say the weight, had brought about this alteration. The heaviest
part of the projectile inclined toward the invisible disc as if it
would fall upon it.

Was it falling? Were the travelers attaining that much desired end?
No. And the observation of a sign-point, quite inexplicable in
itself, showed Barbicane that his projectile was not nearing the
moon, and that it had shifted by following an almost concentric curve.

This point of mark was a luminous brightness, which Nicholl
sighted suddenly, on the limit of the horizon formed by the
black disc. This point could not be confounded with a star.
It was a reddish incandescence which increased by degrees, a
decided proof that the projectile was shifting toward it and
not falling normally on the surface of the moon.

"A volcano! it is a volcano in action!" cried Nicholl; "a
disemboweling of the interior fires of the moon! That world is
not quite extinguished."