y itself, into which the vast body of the water fell, became a
scene of surging madness. The towering walls of water which had stood
up all around the suddenly created aperture hurled themselves back into
the abyss, and down into the great chasm at the bottom of the bay,
which had been made when the motor sent its shock along the great rock
beds. Down upon, and into, this roaring, boiling tumult fell the
tremendous cataract from above, and the harbour became one wild expanse
of leaping maddened waves, hissing their whirling spray high into the
air.

During these few terrific moments other things happened which passed
unnoticed in the general consternation. All along the shores of the
bay and in front of the city the waters seemed to be sucked away,
slowly returning as the sea forced them to their level, and at many
points up and down the harbour there were submarine detonations and
upheavals of the water.

These were caused by the explosion, by concussion, of every torpedo and
submarine battery in the harbour; and it was with this object in view
that the instantaneous motor-bomb had been shot into the mouth of the
bay.

The effects of the discharge of the motor-bomb astonished and even
startled those on board the repellers and the crabs. At the instant of
touching the button a hydraulic shock was felt on Repeller No. 1.
This was supposed to be occasioned the discharge of the motor, but it
was also felt on the other vessels. It was the same shock that had
been felt on shore, but less in degree. A few moments after there was
a great heaving swell of the sea, which tossed and rolled the four
vessels, and lifted the steel protecting net so high that for an
instant parts of it showed themselves above the surface like glistening
sea-ghosts.

Experiments with motor-bombs had been made in unsettled mountainous
districts, but this was the first one which had ever exerted its power
under water.

On shore, in the forts, and in the city no one for an instant supposed
that the terrific phenomenon which had just occurred was in any way due
to the vessels of the Syndicate. The repellers were in plain view, and
it was evident that neither of them had fired a gun. Besides, the
firing of cannon did not produce such effects. It was the general
opinion that there had been an earthquake shock, accompanied by a
cloud-burst and extraordinary convulsions of the sea. Such a
combination of elementary disturbances had never been