rim to this circle, a circle that
was a hundred yards in diameter, in which the water moved from the
circumference to the centre with a velocity increasing with the
contracting of its orbit, from almost dead water in its rim to a
whirling eddy in its centre.

I pulled El Mahdi up and let him drift with the motion of the water. We
swung slowly around the circle, moving inward so gently that our
progress was almost imperceptible.

The panic of men carried out in flood water can be easily understood.
The activity of any power is very apt to alarm when that power is
controlled by no intelligence. It is the unthinking nature of the force
that strikes the terror. Death and the dark would lose much if they lost
this attribute. The water bubbled over the saddle. The horse drifted
like a chip. To my eyes, a few feet above this flood, the water seemed
to lift on all sides, not unlike the sloping rim of some enormous yellow
dish, in which I was moving gradually to the centre.

If I should strike out toward the shore, we should be swimming up-hill,
while the current turning inward was apparently travelling down. This
delusion of grade is well known to the swimmer. It is the chiefest
terror of great water. Expert swimmers floating easily in flood water
have been observed to turn over suddenly, throw up their arms, and go
down. This is probably panic caused by believing themselves caught in
the vortex of a cone, from which there seems no escape, except by the
impossible one of swimming up to its rim, rising on all sides to the
sky.

In a few minutes El Mahdi was in the centre of the eddy, carried by a
current growing always stronger. In this centre the water boiled, but it
was for the most part because of a lashing of surface currents. There
seemed to be no heavy twist of the deep water into anything like a
dangerous whirlpool. Still there was a pull, a tugging of the current to
a centre. Again I was unable to estimate the power of this drag, as it
was impossible to estimate how much resistance was being offered by the
horse.

In the vortex of the eddy the delusion of the vast cone was more
pronounced. It was one of the dangerous elements to be considered. I
observed the horse closely to determine, if possible, whether he
possessed this delusion. If he did, there was not the slightest evidence
of it. He seemed to swim on the wide river with the indifference of
floating timber, his head lying flat, and the yellow waves slipping