At this point the wire entered among the rocks, following the steep side of a narrow ravine.  The settlers followed it at the risk of occasioning a fall of the slightly-balanced rocks, and being dashed into the sea.  The descent was extremely perilous, but they did not think of the danger; they were no longer masters of themselves, and an irresistible attraction drew them towards this mysterious place as the magnet draws iron.

Thus they almost unconsciously descended this ravine, which even in broad daylight would have been considered impracticable.

The stones rolled and sparkled like fiery balls when they crossed through the gleams of light.  Harding was first—­Ayrton last.  On they went, step by step.  Now they slid over the slippery rock; then they struggled to their feet and scrambled on.

At last the wire touched the rocks on the beach.  The colonists had reached the bottom of the basalt cliff.

There appeared a narrow ridge, running horizontally and parallel with the sea.  The settlers followed the wire along it.  They had not gone a hundred paces when the ridge by a moderate incline sloped down to the level of the sea.

The engineer seized the wire and found that it disappeared beneath the waves.

His companions were stupefied.

A cry of disappointment, almost a cry of despair, escaped them!  Must they then plunge beneath the water and seek there for some submarine cavern?  In their excited state they would not have hesitated to do it.

The engineer stopped them.

He led his companions to a hollow in the rocks, and there—­

“We must wait,” said he.  “The tide is high.  At low water the way will be open.”

“But what can make you think-” asked Pencroft.

“He would not have called us if the means had been wanting to enable us to reach him!”

Cyrus Harding spoke in a tone of such thorough conviction that no objection was raised.  His remark, besides, was logical.  It was quite possible that an opening, practicable at low water, though hidden now by the high tide, opened at the foot of the cliff.

There was some time to wait.  The colonists remained silently crouching in a deep hollow.  Rain now began to fall in torrents.  The thunder was re-echoed among the rocks with a grand sonorousness.

The colonists’ emotion was great.  A thousand strange and extraordinary ideas crossed their brains, and they expected some grand and superhuman apparition, which alone could come up to the notion they had formed of the mysterious genius of the island.

At midnight, Harding carrying the lantern, descended to the beach to reconnoiter.

The engineer was not mistaken.  The beginning of an immense excavation could be seen under the water.  There the wire, bending at a right angle, entered the yawning gulf.

Cyrus Harding returned to his companions, and said simply,—­