here
were two more. Besides these there were three or four Martian engineers
watching the machinery in the interior of the building. A number of air
ships were supposed to be on guard around the structure, but possibly
their vigilance had been relaxed, because not long ago the Martians had
sent an expedition against Ceres which had been so successful that the
power of that planet to make an attack upon Mars had for the present
been destroyed.

Supposing us to have been annihilated in the recent battle among the
clouds, they would have no fear or cause for vigilance on our account.

The entrance to the great structure was low--at least, when measured by
the stature of the Martians. Evidently the intention was that only one
person at a time should find room to pass through it.

Drawing cautiously near, we discerned the outlines of two gigantic forms,
standing in the darkness, one on either side of the door. Colonel Smith
whispered to me:

The Disintegrator Again.

"If you will take the fellow on the right, I will attend to the other
one."

Adjusting our aim as carefully as was possible in the gloom, Colonel
Smith and I simultaneously discharged our disintegrators, sweeping
them rapidly up and down in the manner which had become familiar to us
when endeavoring to destroy one of the gigantic Martians with a single
stroke. And so successful were we that the two sentinels disappeared as
if they had been ghosts of the night.

Instantly we all hurried forward and entered the door. Before us extended
a long, straight passage, brightly illuminated by a number of electric
candles. Its polished sides gleamed with blood-red reflections, and
the gallery terminated, at a distance of two or three hundred feet,
with an opening into a large chamber beyond, on the further side of
which we could see part of a gigantic and complicated mass of machinery.

Making as little noise as possible, we pushed ahead along the passage,
but when we had arrived within a distance of a dozen paces from the
inner end, we stopped, and Colonel Smith, getting down upon his knees,
crept forward until he had reached the inner end of the passage. There
he peered cautiously around the edge into the chamber, and, turning his
head a moment later, beckoned us to come forward. We crept to his side,
and, looking out into the vast apartment, could perceive no enemies.

What had become of the sentinels supposed to stand at the inner end of the
passage we cou