insula; but in this case the fixed rifles were fired by means of a
small trickle of water dropping from an upper receptacle into a lower
one. To the latter was tied a cord, the other end of which was
fastened to the trigger. As soon as half a gallon of liquid entered
the lower tin can, resulting in a pressure of about seven pounds on the
trigger, the rifle was fired.

"And there are plenty of discarded tins lying about," thought
Wilmshurst. "It seems strange that methodical Fritz should waste a
good raw-hide thong when simpler and more efficacious means are
available, unless--ah! I wonder if it was a lack of water that made
them clear out?"

Wilmshurst was nothing if not thorough. Before returning with the
joyful news to the kraal he meant to satisfy himself that the Huns had
abandoned all their positions. It would be a bad business if, on the
strength of the young officer's report, the patrol left the village and
attempted to rejoin the main body only to find themselves suddenly
attacked in the open by vastly numerically superior forces.

Checking his direction from time to time by means of his luminous
compass Dudley penetrated nearly a mile into the bush. Everywhere
there were evidences that the enemy had retired in the direction of the
Karewenda Hills, while the not distant sounds of wild animals showed
that the bush was clear of anything of the nature of numerous parties
of human beings.

Satisfied on this point the subaltern was about to retrace his way when
he heard a stealthy footfall on the dew-soddened ground within a few
paces of the spot where he stood.

Softly and deliberately Wilmshurst dropped to the earth, screened by
the broad leaves of a cactus. He could hardly believe the evidence of
his senses when, almost within arm's length, appeared the foremost of a
single file of Haussas--men not only of his own battalion but of his
platoon.

CHAPTER XIX

CORNERED AT LAST

Checking the natural exuberance of his wildly delighted men Wilmshurst
obtained the information that the battalion, acting in conjunction with
a Punjabi infantry regiment and a couple of squadrons of Light Horse,
was about to deliver a surprise attack upon the enemy. Once again the
wily Hun had disappointed the British forces. By means of native
scouts the Germans had learnt of the approach of the relieving forces,
and without waiting to exchange shots the former had effected a prompt
and skilfully-conducted retireme