l of rough projections for
his feet, and in a short time he stood beside Chutney on the ledge.

Wrapping the end of the rope about his arm, Guy called loudly, "Throw
the hook far into the air, colonel. Do you understand?"

"All right," was the immediate response, and in a moment, as the rope
swung over their heads, a heavy sound was heard beneath.

"It reaches the bottom," cried Guy joyfully. "The rope is slack."

He hauled on it eagerly, until ten yards or more lay in coils at his
feet. Then it became taut. The bottom of the cliff was fifty feet below.

The roar of the water was now loud and fierce, but it lay more to one
side. Directly beneath them was solid ground.

With a trembling hand Guy pulled at the hook and secured it to the
ledge. Claiming the right to go first, he let himself over the verge,
and a joyful hail announced that he had reached the bottom in safety.

Melton stuck his torch in a crevice of the rock and started after him.
As his feet touched the ground Guy lit a fresh torch and the light
revealed a level space of white sand, strewn with rocks.

Overhead was the glow of Melton's torch on the ledge, and far beyond on
the dizzy summit of the cliff twinkled the light that the colonel held.

"We are on the bottom," shouted Guy, with all his might.

His voice echoed again and again through the cavern. A reply came back,
but it was almost lost in the roar of the unseen waters.

With feelings that it would be difficult to describe they now advanced
along the sand, bearing the torches high over their heads.

With each step the sound grew louder. It was not the harsh, spasmodic
roar of water dashing among sunken rocks, but resembled rather the swift
outpour of a torrent gliding over a smooth, unbroken bed.

"Here we are," cried Chutney. "I nearly stepped in the water without
seeing it."

He held his torch out with one hand, and its glowing radius revealed a
strange sight.

Twenty yards to their left a rapid, unbroken sheet of water burst with
terrific force from a dark archway in the very face of the smooth
cliff. It was the outlet of the lake.

In width it was about forty feet, though the opposite side of the river
was shrouded in darkness. On the spot where they stood a reflux current
had worn an inlet into the sandy shore, and here a stretch of
comparatively calm water was circling in swirling eddies, a startling
contrast to the furious sweep of the torrent beyond.

Yes, there was no dou