where our speed increased.

My thoughts were now turned to the long journey before me. So deeply
absorbed had I been in the rapid events since I left the observatory,
that I had given little thought to time. My great happiness at meeting
and being with Zarlah had caused me to forget completely the importance
of returning to the observatory within two hours, and as the thought
now flashed through my mind, I hastily consulted the time. To my great
dismay I found I had but twenty minutes in which to cover quarter of
Mars. This I knew was possible, but it left such a narrow margin that
any delay or accident, en route, would prove disastrous to our plans,
thus bringing fatal consequences.

We had now reached the large canal in which we had attained such great
speed, and, rising, we proceeded to pass over it. As we crossed the
banks there came a rushing sound from beneath us, as of a mighty gust of
wind, and, looking through one of the small windows in the side of the
car, I saw in the distance a speck, which, in another moment,
disappeared. Our aerenoid now gently rocked with the motion of a boat
that is in the swell of a passing steamer, and I instantly realized that
another aerenoid, travelling at a terrific speed, had passed in the
canal beneath us.

We had now reached the canal that ran parallel to the one over which we
had just passed. This was in every way similar to the first and was used
by aerenoids going in an opposite direction. Into this canal we turned,
sinking lower as our speed increased, until, when we had reached our
maximum speed, we were travelling not more than thirty feet above the
water. Thus, whenever necessary, we were ready for an instant plunge in
order to reduce our speed, and thus did this simple rule of starting
high and sinking lower as the speed increased make collisions
impossible.

As it was late in the afternoon when we started, the daylight soon
faded, and in a few minutes we had reached complete darkness, the double
line of lights on the canal banks being our only guide. Anxiously did I
count the minutes as we sped along, but knowing the danger of
distracting Reon's attention, even for a moment, while we were
travelling at such a terrific speed, I kept silent, nor did I allow my
manner to give any evidence of my anxiety.

I now realized that if I reached the observatory in time, I would owe my
life to Zarlah. Twice had she reminded me of my duties at the
observatory, and had insisted