ich might well have deprived America of one of
her most beautiful and brilliant heiresses, resulted in nothing more
than a ducking for two men and one girl, a wet, but somehow not
altogether unpleasant walk, and a slight chill from which she had quite
recovered the next morning.

The after consequences of that race for the rescue were of course, quite
another matter.

CHAPTER I

A MOMENTOUS EXPERIMENT

On the first day of July, 1908, a scene which was destined to become
historic took place in the great Lecture Theatre in the Imperial College
at Potsdam. It was just a year and a few days after the swimming race
between John Castellan and the Englishman in Clifden Bay.

There were four people present. The doors were locked and guarded by two
sentries outside. The German Emperor, Count Herold von Steinitz,
Chancellor of the Empire, Field-Marshal Count Friedrich von Moltke,
grandson of the great Organiser of Victory, and John Castellan, were
standing round a great glass tank, twenty-five feet long, and fifteen
broad, supported on a series of trestles. The tank was filled with water
up to within about six inches of the upper edge. The depth was ten feet.
A dozen models of battleships, cruisers and torpedo craft were floating
on the surface of the water. Five feet under the surface, a grey,
fish-shaped craft with tail and fins, almost exactly resembling those of
a flying fish, was darting about, now jumping forward like a cat
pouncing on a bird, now drawing back, and then suddenly coming to a
standstill. Another moment, it sank to the bottom, and lay there as if
it had been a wreck. The next it darted up to the surface, cruised about
in swift curves, turning in and out about the models, but touching none.

Every now and then John Castellan went to a little table in the corner
of the room, on which there was a machine something like a typewriter,
and touched two or three of the keys. There was no visible connection
between them--the machine and the tank--but the little grey shape in
the water responded instantly to the touch of every key.

"That, I hope, will be enough to prove to your Majesty that as submarine
the _Flying Fish_ is quite under control. Of course the real _Flying
Fish_ will be controlled inside, not from outside."

"There is no doubt about the control," said the Kaiser. "It is
marvellous, and I think the Chancellor and the Field Marshal will agree
with me in that."

"Wonderful," said the Chan