Paying no further attention to the calico—which was too spent, anyhow, to attempt to get away—the two, the man and the boy, ran at top speed across the narrow wooden runway which led to the big wheels by which the gateways of the sluice were raised and lowered.
"If Ralph can only hold out!" gasped Jack, who, far up the stream had espied a small black object coming rapidly toward him, which he knew must be the head of his chum. Ralph was swimming easily, taking care not to wind himself, and looking out for any opportunity which might present itself to reach the bank. No sooner did he attempt to cross the current, however, than the water broke over him as if he had been a broached-to canoe. He confined his efforts, therefore, to keeping his head above water. Of the deadly peril that lay ahead of him he had, of course, no knowledge.
"Hurry, Bud!" cried Jack, in an agony of fear that they would be too late.
"All right now, take it easy, Jack. No use hurrying over this job," replied Bud easily, though his drawn face and the sweat on his forehead showed the agitation under which he was laboring.
"Consarn this thing! How's it work!" he muttered angrily, fiddling with the machinery, which was complicated and fitted with elaborate gears and levers to enable the terrific pressure of the water to be handled more easily.
Beneath their feet the stream—a mad torrent above—developed into a screaming, furious flood at the sluiceway. It shot through the narrow confines at tremendous velocity, shaking and tearing at the masonry buttresses as if it would rip them away.
To Jack's excited imagination, it seemed as if the swollen canal was instinct with life and malevolence, and determined to have human life or property in revenge for its confinement.
Suddenly the boy's eyes fell on something he had not noticed before. Beyond the floodgate the engineers of the irrigation canal, finding that the confinement of the water at the sluiceway tended to make the current too savage for mere sandy walls to hold it, had constructed a tunnel. This expedient had been resorted to only after numerous experimental cement retaining walls had been swept away.
Just beyond the buttresses on the other side of the sluice, the entrance of the tunnel yawned blackly. Like a great mouth it swallowed the raging flood as it swept through the sluice.