"Oh for one of the white men's fire-tubes!" he sighed, and even as he spoke a sharp reminder of the efficiency of these same "fire-tubes" whizzed past his ear in the shape of a bullet from Diego's revolver.

In a few steps the old black was beside his young leader and with a couple of strokes of his keen blade had set him free.

"Quick, Sikaso; the canoes—we must pursue him. Call the boys and Ben while I cast off the canoes. Quick, we have not a minute to lose."

Although Diego in his hurry had not carried off the map but left it lying on the ground, still Frank realized that the Portuguese had not actually needed the document to aid Muley-Hassan to find the cache. The Arab was no doubt familiar with the location anyway, but to head off all danger of the boys getting there first, it was vital to stop Diego at all costs. In a few bounds Frank reached the little indentation in the bank where the canoes were kept.

As he gained it he fell back with a groan and, brave boy as he was, he leaned weakly against a tree for support as the true extent of the crushing disaster that had occurred was borne in on him.

The canoes were gone!

The cunning rascal, Diego, had devised his plan well.

The painters of all the craft had been cut, and by this time they were doubtless miles down the stream.

CHAPTER VIII