r its products, and when the savages talked of seaweed
he thought they meant green wood. Fortunately for him, the ascending
clouds of smoke missed the cave, or infallibly he must have been
stifled.

"Lie flat on the rock!" gasped Jenks. Careless of waste, he poured
water over a coat and made Iris bury her mouth and nose in the wet
cloth. This gave her immediate relief, and she showed her woman's wit
by tying the sleeves of the garment behind her neck. Jenks nodded
comprehension and followed her example, for by this means their hands
were left free.

The black cloud grew more dense each few seconds. Nevertheless, owing
to the slope of the ledge, and the tendency of the smoke to rise, the
south side was far more tenable than the north. Quick to note this
favorable circumstance, the sailor deduced a further fact from it. A
barrier erected on the extreme right of the ledge would be a material
gain. He sprang up, dragged the huge tarpaulin from its former
location, and propped it on the handle of the pickaxe, driven by one
mighty stroke deep into a crevice of the rock.

It was no mean feat of strength that he performed. He swung the heavy
and cumbrous canvas into position as if it were a dust cloth. He
emerged from the gloom of the driven cloud red-eyed but triumphant.
Instantly the vapor on the ledge lessened, and they could breathe, even
talk. Overhead and in front the smoke swept in ever-increasing density,
but once again the sailor had outwitted the Dyaks' manoeuvres.

"We have won the first rubber," he whispered to Iris.

Above, beneath, beyond, they could see nothing. The air they breathed
was hot and foetid. It was like being immured in a foul tunnel and
almost as dark. Jenks looked over the parapet. He thought he could
distinguish some vague figures on the sands, so he fired at them. A
volley of answering bullets crashed into the rock on all sides. The
Dyaks had laid their plans well this time. A firing squad stationed
beyond the smoke area, and supplied with all the available guns,
commenced and kept up a smart fusillade in the direction of the ledge
in order to cover the operations of the scaling party.

Jenks realized that to expose himself was to court a serious wound and
achieve no useful purpose. He fell back out of range, laid down his
rifle and grabbed the crowbar. At brief intervals a deep hollow boom
came up from the valley. At first it puzzled them until the sailor hit
upon an explanation. Mir Jan w