eeded in grasping the hand-rail, but the boy would have
plunged overboard had I not fortunately grasped his ankle as he was
already partially over.

Unguided, our vessel careened wildly in its mad flight, rising ever
nearer the rocks above. It took but an instant, however, for me to
regain the levers, and with the roof barely fifty feet above I turned
her nose once more into the horizontal plane and headed her again for
the black mouth of the shaft.

The collision had retarded our progress and now a hundred swift scouts
were close upon us. Xodar had told me that ascending the shaft by
virtue of our repulsive rays alone would give our enemies their best
chance to overtake us, since our propellers would be idle and in rising
we would be outclassed by many of our pursuers. The swifter craft are
seldom equipped with large buoyancy tanks, since the added bulk of them
tends to reduce a vessel's speed.

As many boats were now quite close to us it was inevitable that we
would be quickly overhauled in the shaft, and captured or killed in
short order.

To me there always seems a way to gain the opposite side of an
obstacle. If one cannot pass over it, or below it, or around it, why
then there is but a single alternative left, and that is to pass
through it. I could not get around the fact that many of these other
boats could rise faster than ours by the fact of their greater
buoyancy, but I was none the less determined to reach the outer world
far in advance of them or die a death of my own choosing in event of
failure.

"Reverse?" screamed Xodar, behind me. "For the love of your first
ancestor, reverse. We are at the shaft."

"Hold tight!" I screamed in reply. "Grasp the boy and hold tight--we
are going straight up the shaft."

The words were scarce out of my mouth as we swept beneath the
pitch-black opening. I threw the bow hard up, dragged the speed lever
to its last notch, and clutching a stanchion with one hand and the
steering-wheel with the other hung on like grim death and consigned my
soul to its author.

I heard a little exclamation of surprise from Xodar, followed by a grim
laugh. The boy laughed too and said something which I could not catch
for the whistling of the wind of our awful speed.

I looked above my head, hoping to catch the gleam of stars by which I
could direct our course and hold the hurtling thing that bore us true
to the centre of the shaft. To have touched the side at the speed w