Great blocks of that basalt, which, according to Bischof, takes three hundred and fifty millions of years to cool, strewed the plain, very confused in some places. However, there were here no traces of lava, which was spread more particularly over the northern slopes.

Cyrus Harding expected to reach, without incident, the course of the creek, which he supposed flowed under the trees at the border of the plain, when he saw Herbert running hastily back, while Neb and the sailor were hiding behind the rocks.

"What's the matter, my boy?" asked Spilett.

"Smoke," replied Herbert. "We have seen smoke among the rocks, a hundred paces from us."

"Men in this place?" cried the reporter.

"We must avoid showing ourselves before knowing with whom we have to deal," replied Cyrus Harding. "I trust that there are no natives on this island; I dread them more than anything else. Where is Top?"

"Top is on before."

"And he doesn't bark?"

"No."

"That is strange. However, we must try to call him back."

In a few moments, the engineer, Gideon Spilett, and Herbert had rejoined their two companions, and like them, they kept out of sight behind the heaps of basalt.

From thence they clearly saw smoke of a yellowish color rising in the air.

Top was recalled by a slight whistle from his master, and the latter, signing to his companions to wait for him, glided away among the rocks. The colonists, motionless, anxiously awaited the result of this exploration, when a shout from the engineer made them hasten forward. They soon joined him, and were at once struck with a disagreeable odor which impregnated the atmosphere.

The odor, easily recognized, was enough for the engineer to guess what the smoke was which at first, not without cause, had startled him.

"This fue," said he, "or rather, this smoke is produced by nature alone. There is a sulphur spring there, which will cure all our sore throats."

"Captain!" cried Pencroft. "What a pity that I haven't got a cold!"

The settlers then directed their steps towards the place from which the smoke escaped. They there saw a sulphur spring which flowed abundantly between the rocks, and its waters discharged a strong sulphuric acid odor, after having absorbed the oxygen of the air.

Cyrus Harding, dipping in his hand, felt the water oily to the touch. He tasted it and found it rather sweet. As to its temperature, that he estimated at ninety-five degrees Fahrenheit. Herbert having asked on what he based this calculation,--

"Its quite simple, my boy," said he, "for, in plunging my hand into the water, I felt no sensation either of heat or cold. Therefore it has the same temperature as the human body, which is about ninety-five degrees."

The sulphur spring not being of any actual use to the settlers, they proceeded towards the thick border of the forest, which began some hundred paces off.

There, as they had conjectured, the waters of the stream flowed clear and limpid between high banks of red earth, the color of which betrayed the presence of oxide of iron. From this color, the name of Red Creek was immediately given to the watercourse.

It was only a large stream, deep and clear, formed of the mountain water, which, half river, half torrent, here rippling peacefully over the sand, there falling against the rocks or dashing down in a cascade, ran towards the lake, over a distance of a mile and a half, its breadth varying from thirty to forty feet. Its waters were sweet, and it was supposed that those of the lake were so also. A fortunate circumstance, in the event of their finding on its borders a more suitable dwelling than the Chimneys.

As to the trees, which some hundred feet downwards shaded the banks of the creek, they belonged, for the most part, to the species which abound in the temperate zone of America and Tasmania, and no longer to those coniferae observed in that portion of the island already explored to some miles from Prospect Heights. At this time of the year, the commencement of the month of April, which represents the month of October, in this hemisphere, that is, the beginning of autumn, they were still in full leaf. They consisted principally of casuarinas and eucalypti, some of which next year would yield a sweet manna, similar to the manna of the East.