For nearly three hundred paces the tunnel sloped steeply downwards, the walls remaining perfectly dry—a circumstance that showed the passage was still under the Island. Beyond that distance, although the tunnel was still on the down grade, the roof and walls showed signs of moisture, while in place of the dry dust the floor was ankle deep in slime. Overhead a deep muffled roar betokened the fact that the sea was only separated from the Scouts by a few feet of rock, through which the sound of the ground-swell was audible.
Suddenly Atherton came to a halt, and held his lantern above his head.
"Anything wrong?" asked Phillips.
"It's all right here," he announced. "The air is quite fresh. I've found something: looks like a seat with some carving above it."
On the right-hand side of the tunnel, in a cavity three feet in depth and extending the whole height of the passage, was a stone bench. Above the latter were several carvings in relief, all more or less damaged by the ravages of time and the moisture of the rock.
"Here's a crucifix," said Atherton, pointing to a Cornish cross. "And there's some inscription underneath. I can't quite make out the letters, though."
"I can read one word," said Green. "The first letter is supposed to be a P. The word is 'Pax.'"
"And here's a date: MCCLI—that's 1251," announced Atherton. "This must be a sort of half-way resting place for the monks who visited the oratory. If it's not half way it's at the lowest level of the tunnel, for the gradient is now on the ascent. But let's go on. I wonder where we shall find ourselves when we come to the end."
"Why, at the end, of course," replied Everest. "Where else did you expect?"
The forward movement was resumed, Atherton placing the previous distance between him and the next Scout. At length the rocky walls began to show less signs of moisture, and the Scouts knew that they had passed under Seal Bay and were now not far from, if not actually underneath, the village of Polkerwyck.