“But don’t you think,” suggested Otto, “that the men whose graves we have found may have used it all up?”
Otto was right. Not a scrap of timber or cordage of any kind was to be found after a most diligent search, and they were about to give it up in despair, when Pauline remembered the bay where they had been cast ashore, and which we have described as being filled with wreckage.
In truth, this bay and the reef with its group of islands lay right in the track of one of those great ocean currents which, as the reader probably knows, are caused by the constant circulation of all the waters of the sea between the equator and the poles. This grand and continuous flow is caused by difference of temperature and density in sea-water at different places. At the equator the water is warm, at the poles it is cold. This alone would suffice to cause circulation—somewhat as water circulates in a boiling pot—but other active agents are at work. The Arctic and Antarctic snows freshen the sea-water as well as cool it, while equatorial heat evaporates as well as warms it, and thus leaves a superabundance of salt and lime behind. The grand ocean current thus caused is broken up into smaller streams, and the courses of these are fixed by the conformation of land—just as a river’s flow is turned right or left, and sometimes backward in eddies, by the form of its banks and bottom. Trade winds, and the earth’s motion on its axis, still further modify the streams, both as to direction and force.
It was one of those currents, then, which flowed past the reef and sometimes cast vessels and wreckage on its shores.
Hastening to the bay, they accordingly found enough of broken spars and planks, to have made half a dozen rafts, twice the size of that required to go off with to the wreck; so to work they went at once with eager enthusiasm.
“Hold on!” shouted Dominick, after a few spars had been collected and dragged up on the sand.
Otto and Pauline paused in their labour, and looked anxiously at their brother, for his face wore a perplexed look.
“We have forgotten that it is impossible to shove a raft of any size, big or little, through these huge breakers, so as to get it round the point, to where the wreck lies.”
“Well, then,” cried Otto, with the ready assurance of ignorance, “we’ll just drag it overland to the wreck, and launch it there.”
“But, Otto, you have not taken into consideration the fact that our raft must be so large that, when finished, the dragging of it over rough ground would require three or four horses instead of three human beings.”