The colonists first visited the valley opening to the south of the volcano, and which first received the waters of Falls River. There Ayrton showed them the cavern where the convicts had taken refuge, and in which he had been imprisoned until his removal to the corral. This cavern was just as Ayrton had left it. They found there a considerable quantity of ammunition and provisions, conveyed thither by the convicts in order to form a reserve.
The whole of the valley bordering on the cave, shaded by fir and other trees, was thoroughly explored, and on turning the point of the southwestern spur, the colonists entered a narrower gorge similar to the picturesque columns of basalt on the coast. Here the trees were fewer. Stones took the place of grass. Goats and musmons gambolled among the rocks. Here began the barren part of the island. It could already be seen that, of the numerous valleys branching off at the base of Mount Franklin, three only were wooded and rich in pasturage like that of the corral, which bordered on the west on the Falls River valley, and on the east on the Red Creek valley. These two streams, which lower down became rivers by the absorption of several tributaries, were formed by all the springs of the mountain and thus caused the fertility of its southern part. As to the Mercy, it was more directly fed from ample springs concealed under the cover of Jacamar Wood, and it was by springs of this nature, spreading in a thousand streamlets, that the soil of the Serpentine Peninsula was watered.
Now, of these three well-watered valleys, either might have served as a retreat to some solitary who would have found there everything necessary for life. But the settlers had already explored them, and in no part had they discovered the presence of man.
Was it then in the depths of those barren gorges, in the midst of the piles of rock, in the rugged northern ravines, among the streams of lava, that this dwelling and its occupant would be found?
The northern part of Mount Franklin was at its base composed solely of two valleys, wide, not very deep, without any appearance of vegetation, strewn with masses of rock, paved with lava, and varied with great blocks of mineral. This region required a long and careful exploration. It contained a thousand cavities, comfortless no doubt, but perfectly concealed and difficult of access.
The colonists even visited dark tunnels, dating from the volcanic period, still black from the passage of the fire, and penetrated into the depths of the mountain. They traversed these somber galleries, waving lighted torches; they examined the smallest excavations; they sounded the shallowest depths, but all was dark and silent. It did not appear that the foot of man had ever before trodden these ancient passages, or that his arm had ever displaced one of these blocks, which remained as the volcano had cast them up above the waters, at the time of the submersion of the island.
However, although these passages appeared to be absolutely deserted, and the obscurity was complete, Cyrus Harding was obliged to confess that absolute silence did not reign there.
On arriving at the end of one of these gloomy caverns, extending several hundred feet into the interior of the mountain, he was surprised to hear a deep rumbling noise, increased in intensity by the sonorousness of the rocks.
Gideon Spilett, who accompanied him, also heard these distant mutterings, which indicated a revivification of the subterranean fires. Several times both listened, and they agreed that some chemical process was taking place in the bowels of the earth.
"Then the volcano is not totally extinct?" said the reporter.
"It is possible that since our exploration of the crater," replied Cyrus Harding, "some change has occurred. Any volcano, although considered extinct, may evidently again burst forth."
"But if an eruption of Mount Franklin occurred," asked Spilett, "would there not be some danger to Lincoln Island?"
"I do not think so," answered the reporter.