as it has become, I have no desire to have it broken by any repetition of the perils and adventures of yesterday.
Thursday, August 20. The wind is now N. N. E., and blows very irregularly. It has changed to fitful gusts. The temperature is exceedingly high. We are now progressing at the average rate of about ten miles and a half per hour. About twelve o'clock a distant sound as of thunder fell upon our ears. I make a note of the fact with out even venturing a suggestion as to its cause. It was one continuous roar as of a sea falling over mighty rocks.
"Far off in the distance," said the Professor dogmatically, "there is some rock or some island against which the sea, lashed to fury by the wind, is breaking violently."
Hans, without saying a word, clambered to the top of the mast, but could make out nothing. The ocean was level in every direction as far as the eye could reach.
Three hours passed away without any sign to indicate what might be before us. The sound began to assume that of a mighty cataract. I expressed my opinion on this point strongly to my uncle. He merely shook his head. Are we advancing towards some mighty waterfall which shall cast us into the abyss? Probably this mode of descending into the abyss may be agreeable to the Professor, because it would be something like the vertical descent he is so eager to make. I entertain a very different view. Whatever be the truth, it is certain that not many leagues distant there must be some very extraordinary phenomenon, for as we advance the roar becomes something mighty and stupendous. Is it in the water, or in the air?
I cast hasty glances aloft at the suspended vapors, and I seek to penetrate their mighty depths. But the vault above is tranquil. The clouds, which are now elevated to the very summit, appear utterly still and motionless, and completely lost in the irradiation of electric light. It is necessary, therefore, to seek for the cause of this phenomenon elsewhere.
I examine the horizon, now perfectly calm, pure and free from all haze. Its aspect still remains unchanged. But if this awful noise proceeds from a cataract—if, so to speak in plain English, this vast interior ocean is precipitated into a lower basin—if these tremendous roars are produced by the noise of falling waters, the current would
