The plesiosaurus, a serpent with a cylindrical body and a short tail, has four flappers or paddles to act like oars. Its body is entirely covered with a thick armour of scales, and its neck, as flexible as a swan's, rises thirty feet above the waves.

Those huge creatures attacked each other with the greatest animosity. They heaved around them liquid mountains, which rolled even to our raft and rocked it perilously. Twenty times we were near capsizing. Hissings of prodigious force are heard. The two beasts are fast locked together; I cannot distinguish the one from the other. The probable rage of the conqueror inspires us with intense fear.

One hour, two hours, pass away. The struggle continues with unabated ferocity. The combatants alternately approach and recede from our raft. We remain motionless, ready to fire. Suddenly the ichthyosaurus and the plesiosaurus disappear below, leaving a whirlpool eddying in the water. Several minutes pass by while the fight goes on under water.

All at once an enormous head is darted up, the head of the plesiosaurus. The monster is wounded to death. I no longer see his scaly armour. Only his long neck shoots up, drops again, coils and uncoils, droops, lashes the waters like a gigantic whip, and writhes like a worm that you tread on. The water is splashed for a long way around. The spray almost blinds us. But soon the reptile's agony draws to an end; its movements become fainter, its contortions cease to be so violent, and the long serpentine form lies a lifeless log on the labouring deep.

As for the ichthyosaurus - has he returned to his submarine cavern? or will he reappear on the surface of the sea?

CHAPTER XXXIV.

THE GREAT GEYSER

_Wednesday, August 19_. - Fortunately the wind blows violently, and has enabled us to flee from the scene of the late terrible struggle. Hans keeps at his post at the helm. My uncle, whom the absorbing incidents of the combat had drawn away from his contemplations, began again to look impatiently around him.

The voyage resumes its uniform tenor, which I don't care to break with a repetition of such events as yesterday's.

Thursday, Aug. 20. - Wind N.N.E., unsteady and fitful. Temperature high. Rate three and a half leagues an hour.

About noon a distant noise is heard. I note the fact without being able to explain it. It is a continuous roar.

"In the distance," says the Professor, "there is a rock or islet, against which the sea is breaking."

Hans climbs up the mast, but sees no breakers. The ocean' is smooth and unbroken to its farthest limit.

Three hours pass away. The roarings seem to proceed from a very distant waterfall.

I remark upon this to my uncle, who replies doubtfully: "Yes, I am convinced that I am right." Are we, then, speeding forward to some cataract which will cast us down an abyss? This method of getting on may please the Professor, because it is vertical; but for my part I prefer the more ordinary modes of horizontal progression.

At any rate, some leagues to the windward there must be some noisy phenomenon, for now the roarings are heard with increasing loudness. Do they proceed from the sky or the ocean?

I look up to the atmospheric vapours, and try to fathom their depths. The sky is calm and motionless. The clouds have reached the utmost limit of the lofty vault, and there lie still bathed in the bright glare of the electric light. It is not there that we must seek for the cause of this phenomenon. Then I examine the horizon, which is unbroken and clear of all mist. There is no change in its aspect. But if this noise arises from a fall, a cataract, if all this ocean flows away headlong into a lower basin yet, if that deafening roar is produced by a mass of falling water, the current must needs accelerate, and its increasing speed will give me the measure of the peril that threatens us. I consult the current: there is none. I throw an empty bottle into the sea: it lies still.

About four Hans rises, lays hold of the mast, climbs to its top. Thence his eye sweeps a large area of sea, and it is fixed upon a point.