Towards seven in the morning the position was no longer tenable by the colonists, who accordingly took shelter in the borders of Jacamar Wood. Not only did the projectiles begin to rain around them, but the lava, overflowing the bed of Red Creek, threatened to cut off the road to the corral. The nearest rows of trees caught fire, and their sap, suddenly transformed into vapour, caused them to explode with loud reports, whilst others, less moist, remained unhurt in the midst of the inundation. The colonists had again taken the road to the corral. They proceeded but slowly, frequently looking back; but, in consequence of the inclination of the soil, the lava gained rapidly in the east, and as its lower waves became solidified, others at boiling heat covered them immediately. Meanwhile, the principal stream of Red Creek valley became more and more menacing. All this portion of the forest was on fire, and enormous wreaths of smoke rolled over the trees, whose trunks were already consumed by the lava. The colonists halted near the lake, about half a mile from the mouth of Red Creek. A question of life or death was now to be decided. Cyrus Harding, accustomed to the consideration of important crises, and aware that he was addressing men capable of hearing the truth, whatever it might be, then said-- "Either the lake will arrest the progress of the lava, and a part of the island will be preserved from utter destruction, or the stream will overrun the forests of the Far West, and not a tree or plant will remain on the surface of the soil. We shall have no prospect but that of starvation upon these barren rocks--a death which will probably be anticipated by the explosion of the island." "In that case," replied Pencroft, folding his arms and stamping his foot, "what's the use of working any longer on the vessel?" "Pencroft," answered Cyrus Harding, "we must do our duty to the last!" At this instant the river of lava, after having broken a passage through the noble trees it devoured in its course, reached the borders of the lake. At this point there was an elevation of the soil which, had it been greater, might have sufficed to arrest the torrent. "To work!" cried Cyrus Harding. The engineer's thought was at once understood. It might be possible to dam, as it were, the torrent, and thus compel it to pour itself into the lake. The colonists hastened to the dockyard. They returned with shovels, picks, axes, and by means of banking the earth with the aid of fallen trees they succeeded in a few hours in raising an embankment three feet high and some hundreds of paces in length. It seemed to them, when they had finished, as if they had scarcely been working more than a few minutes.