and myself at once clambered out upon a strong
limb.

For a moment I feared our arrival had been betrayed on account of the
altogether too noisy contest that arose between Colonel Smith and
Mr. Phillips as to which of them should assist Aina. To settle the
dispute I took charge of her myself.

At length we were all safely in the tree.

Then followed the still more dangerous undertaking of descending from
this great height to the ground. Fortunately, the branches were very
close together and they extended down within a short distance of the
soil. So the actual difficulties of the descent were not very great
after all. The one thing that we had particularly to bear in mind was
the absolute necessity of making no noise.

At length the descent was successfully accomplished, and we all five
stood together in the shadow at the foot of the great tree. The grove
was so thick around that while there was an abundance of electric lights
among the trees, their illumination did not fall upon us where we stood.

Peering cautiously through the vistas in various directions, we
ascertained our location with respect to the wall of the building. Like
all the structures that we had seen on Mars, it was composed of polished
red metal.

Looking for an Entrance.

"Where is the entrance?" inquired Mr. Edison, in a whisper.

"Come softly this way, and look out for the sentinel," replied Aina.

Gripping our disintegrators firmly, and screwing up our courage, with
noiseless steps we followed the girl among the shadows of the trees.

We had one very great advantage. The Martians had evidently placed so
much confidence in the electric network which surrounded the power house
that they never dreamed of enemies being able to penetrate it--at least,
without giving warning of their coming.

But the hole which we had blown in this network with the disintegrators
had been made noiselessly, and Mr. Edison believed, since no enemies
had appeared, that our operations had not been betrayed by any automatic
signal to watchers inside the building.

Consequently, we had every reason to think that we now stood within
the line of defence, in which they reposed the greatest confidence,
without their having the least suspicion of our presence.

Aina assured us that on the occasion of her former visit to the power
house there had been but two sentinels on guard at the entrance. At the
inner end of a long passage leading to the interior, she said, t