“Thirty miles!” returned Spilett.  “That would be a long day’s march.  Nevertheless, I think that we should return to Granite House by the south coast.”

“But,” observed Herbert, “from Claw Cape to Granite House there must be at least another ten miles.

“Make it forty miles in all,” replied the engineer, “and do not hesitate to do it.  At least we should survey the unknown shore, and then we shall not have to begin the exploration again.”

“Very good,” said Pencroft.  “But the boat?”

“The boat has remained by itself for one day at the sources of the Mercy,” replied Gideon Spilett; “it may just as well stay there two days!  As yet, we have had no reason to think that the island is infested by thieves!”

“Yet,” said the sailor, “when I remember the history of the turtle, I am far from confident of that.”

“The turtle! the turtle!” replied the reporter.  “Don’t you know that the sea turned it over?”

“Who knows?” murmured the engineer.

“But,—­” said Neb.

Neb had evidently something to say, for he opened his mouth to speak and yet said nothing.

“What do you want to say, Neb?” asked the engineer.

“If we return by the shore to Claw Cape,” replied Neb, “after having doubled the Cape, we shall be stopped—­”

“By the Mercy! of course,” replied Herbert, “and we shall have neither bridge nor boat by which to cross.”

“But, captain,” added Pencroft, “with a few floating trunks we shall have no difficulty in crossing the river.”

“Never mind,” said Spilett, “it will be useful to construct a bridge if we wish to have an easy access to the Far West!”

“A bridge!” cried Pencroft.  “Well, is not the captain the best engineer in his profession?  He will make us a bridge when we want one.  As to transporting you this evening to the other side of the Mercy, and that without wetting one thread of your clothes, I will take care of that.  We have provisions for another day, and besides we can get plenty of game.  Forward!”

The reporter’s proposal, so strongly seconded by the sailor, received general approbation, for each wished to have their doubts set at rest, and by returning by Claw Cape the exploration would he ended.  But there was not an hour to lose, for forty miles was a long march, and they could not hope to reach Granite House before night.

At six o’clock in the morning the little band set out.  As a precaution the guns were loaded with ball, and Top, who led the van, received orders to beat about the edge of the forest.

From the extremity of the promontory which formed the tail of the peninsula the coast was rounded for a distance of five miles, which was rapidly passed over, without even the most minute investigations bringing to light the least trace of any old or recent landings; no debris, no mark of an encampment, no cinders of a fire, nor even a footprint!