“Is that a thunder storm?” questioned Frank of the sailor.
“I t’ink no sturm. I t’ink dat be da breakers. But no can see him.”
They looked around for the breakers, or for some sign of reefs, but darkness was now settled upon every side. The booming continued at long intervals, but they concluded that it must be miles away.
“I never heard of anything like it,” came from Mark. “First the dust and now this noise. It’s certainly strange.”
“The raft is moving swifter, too,” returned Frank. “I’ve noticed it for some time. There must be some sort of a current here.”
Their attention was now directed to this new discovery, and soon they noticed that the raft was certainly moving in a direction south-east by south, to use the nautical term. And it was going at the rate of twenty or thirty miles an hour!
“The whole ocean looks different here,” said Mark, “What do you make of it?” he asked of Sven Orlaff.
The Norwegian could not explain. He said the water had an appearance which he had never seen. On the surface was a sort of scum which, on being examined, proved to be, in part, of the dust they had previously noticed.
“Put your hand into the water,” cried Frank. “It is surely warmer!”
They did so. Frank was right, the water was at least ten degrees hotter than it had been. Not only this, it was growing hotter each minute, until it got so they could scarcely put their hands into it.