r and beyond her quarry. She had
then to turn and circle overhead, awaiting the chance of shattering her
enemy as she dived.

U75 was already disappearing beneath the waves.

She dived at a very oblique angle, steeper than she had ever done
before.

Ross and Vernon, unaware of what was taking place, thought for a moment
that the submarine was plunging headlong to the bed of the Bristol
Channel. They had to cling desperately to the nearest object to hand
to prevent themselves from sliding violently against a transverse
bulkhead.

Even as they clung they heard two muffled detonations in quick
succession, followed by a distinct quiver of the submarine's hull--a
movement that bore a marked difference to the vibrations under the
pulsations of the motors.

The sea-plane had dropped two bombs, both of which very nearly attained
their object.

Kapitan Schwalbe did not bring the submarine to a horizontal position
until she had reached a depth of fifteen fathoms. At that depth he was
safe, both from explosives dropped from the sea-plane and also from
observation. The water being still agitated, made it impossible for
the observer on the biplane to follow the movements of a dark shadow
fathoms deep. For once, the rough seas had been kind to U75; but the
fact remained that she was still badly in want of fuel, while his last
attempt had resulted in the loss of an officer and six men, who could
not well be spared.

Although the sea-plane had failed to achieve her object by pulverizing
the U-boat's hull, the moral and material result was none the less
effective.

The explosion of the bombs had started several of U75's plates.
Numerous jets of water were spurting through the seams, the inrush
requiring all the mechanical appliances at the command of the modern
pirate to keep the leaks under control, while the badly-jarred nerves
of Kapitan Schwalbe and his crew warned them of the grave risks they
ran in attempting to try conclusions with even an apparently harmless
craft displaying the Red Ensign of Britain's Mercantile Marine.

CHAPTER IX

The Landing at Port Treherne

"I wonder if they'll let us go on deck," remarked Vernon Haye. "If so,
I vote we have a shot at getting ashore. What sort of show is Port
Treherne?"

"I know it fairly well," replied Ross. "It's the most forsaken crib
you are ever likely to meet along the coast. It's a deep gully in the
cliffs. There's only one small landing-place--a fl