conversation as he crouched in his diving-sphere in the purple darkness of the marine depths. Yes, old Osborne would believe him. The diary must be written for Osborne's eyes.

bbot sent another beam from his pocket light suddenly out into the water; and this time he surprised several of the peculiar fish. These, like the first, had arms and hands and high intelligent foreheads.

Then suddenly Abbot laughed a harsh laugh. Old Osborne had been wrong in one thing, namely in saying that the super-race of the deep would never be a menace to anyone. They were being a menace to George Abbot, right now, for it was undoubtedly they who had cut his cables. Probably they were possessed of much the same scientific curiosity with regard to him as he was with regard to them, and so they had determined to secure him as a museum specimen.

The idea was a weird one. He laughed again, mirthlessly.

"What is the matter, sir?" came an anxious voice in his ear-phones.

"Hurry that grapple!" was his reply. "I have found out what cut my cables. There are some very intelligent-looking fish down here, and I think they want me for—"

An ominous click sounded in his ears. Then silence.

"Hello! Hello there!" he shouted. "Can you hear me up on the boat?"

But no answer came back. The line remained dead. The strange fish had cut George Abbot's last contact with the upper world. The grapple-hooks could never find him now, for there was now not even a telephone cable to guide them down to his sphere.

The realization that he was hopelessly lost, and that he had not much longer to live, came as a real relief to him, after the last few moments of frantic uncertainty.

oping that his sphere would eventually be found, even though too late to do him any good, he set assiduously to work jotting down all the details which he could remember of those strange denizens of the deep, the man-handed sharks, which he was now firmly convinced were the cause of his present predicament.

He stared out through one of his windows into the brilliant blue darkness, but did not turn on his flashlight. How near were these enemies of his, he wondered?

The presence of those menacing man-sharks, just outside the four-inch-thick steel shell, which withstood a ton of pressure for each square inch of its surface, began to obsess young Abbot. What were they doing out there in the watery-blue midnight? Perhaps, having secured his sphere as a scientific specimen, they were already preparing to cut into it so as to see what was inside. That these fish could cut through four inches of steel was not so improbable as it sounded, for had they not already succeeded in severing a rubber cable an inch and a half thick, containing two heavy copper wires, and also two inches of the finest, non-kinking steel rope!

The young scientist flashed his pocket torch out through the thick quartz pane, but his enemies were nowhere in sight. Then he fell to calculating his oxygen supply. His normal consumption was about half a quart per minute, at which rate his two tanks would be good for thirty-six hours. His chemical racks contained enough soda-lime to absorb the excess carbon dioxide, enough calcium chloride to keep down the humidity and enough charcoal to sweeten the body odors for much more than that period.

For a moment, the thought of these facts encouraged him. He had been down less than two hours. Perhaps the boat above him could affect his rescue in the more than thirty-four hours which remained!

ut then he realized that he had failed to take into consideration the near-freezing temperature of the ocean depths. This temperature he knew to be in the neighborhood of 39 degrees Fahrenheit—even though no thermometer hung outside his window, as none could withstand the frightful pressures at the bottom of the sea. For it is one of the remarkable facts of inductive science that man has been able to figure out a priori that the temperature at all deep points of the ocean, tropic as well as arctic, must always be stable at approximately 39 degrees.

Abbot was clad only in a light cotton sailor suit, and now that his source of heat had been cut off by the severing of his power lines, his prison was rapidly becoming unbearably chilly. His thick steel sphere constituted such a perfect transmitter of heat that he might almost as well have been actually swimming in water of 39 degrees temperature, so far as comfort was concerned.

Abbot's emotions ran all the gamut from stupefaction, through dull calmness, clear-headed thought, intense but aimless mental activity, nervousness, frenzy, and insane delirium, back to stupefaction again.

During one of his periods of calmness, he figured out what an almost total impossibility there was of the chance that his ship, one mile above him on the surface, could ever find his sphere with grappling hooks. Yet he prayed for that chance. A single chance in a million sometimes does happen.

everal hours had by now elapsed since the parting of the young scientist's cables. It was bitterly cold inside the sphere. In order to keep warm, he had to exercise during his calm moments as systematically as his cramped quarters would permit. During his frantic moments he got plenty of exercise automatically. And of course all this movement used up more than the normal amount of oxygen, so that he was forced to open the valves on his tanks to two or three times their normal flow. His span of further life was thereby cut to ten or twelve hours, if indeed he could keep himself warm for that long.

Why didn't the people on the boat do something!

He was just about to indulge in one of his frantic fits of despair, when he heard or felt—the two senses being strangely commingled in his present situation—a clank or thump upon the top of his bathysphere. Instantly hope flooded him. Could it be that the one chance in a million had actually happened, and that a grapple from the boat above had actually found him?

With feverish expectation, he pressed the button of his little electric pocket flashlight, and sent its feeble beam out through one of the quartz-glass windows into the blue-black depths beyond.

No hooks in front of this window. He tried the others. No hooks there, either. But he did see plenty of the superhuman fish. Eighteen of them, he counted, in sight at one time. And also two huge snake-like creatures with crested backs and maned heads, veritable sea-serpents.

As there was nothing the young man could do to assist in the grappling of his sphere by his friends in the boat above, he devoted his time to jotting down a detailed description of these two new beasts and of their behavior.

One of the sharks appeared to be leading or driving them up to the bathysphere; and when they got close enough, Abbot was surprised to see that they wore what appeared to be a harness!

he clanking upon the bathysphere continued, and now the young man learned its cause. It was not the grapple hooks from his ship, but chains—chains which the man-armed sharks were