There was now no chance to avert the explosion of the time bomb within the coal barge. On the appointed time it would go off as arranged and unless the mechanism by some freak of luck refused to work; but the chances on this score were few indeed. The mechanism represented the very latest scientific thought and the bomb was essentially for submarine work of this character. "Looks, chum, as though we were in for the fireworks," smiled Dick, who was as cool as though he were standing on the twenty-five yard line at Brighton waiting for the ball to be passed for a try at a goal from the field. Jay had not yet given up hope of getting the _Nautilus_ moving, or of escaping from her in some way. He looked at his watch. Little more than a minute until the bomb would go off! "Why in the name of sense don't they start the engines of the _Jules Verne_ and back her away from the barge?" he ejaculated in consternation. By moving the _Jules Verne_ the _Nautilus_ also would be moved. "Didn't you hear Larry say there was a breakdown in the engine room of the _Jules Verne_ that was the cause of the whole trouble?" put back Dick, who was by far the more self-possessed of the two. Slowly Jay shook his head in affirmation. Memory had fled with the rapid flow of events of the last quarter of an hour. Was it any wonder his senses reeled? Two youths completely trapped in a diving chamber that was poised directly over a coal barge in which a high explosive time bomb was set to go off now at any time! There was a chance, of course, that the detonation might not be severe enough to damage the _Nautilus_. The bomb might explode outward or downward instead of spending its energy upward under the keel of the diving bell. In that event the shock might not be sufficient to rend the seams of the light steel chamber in which the Brighton boys were crouched awaiting the inevitable crash. If--but no one could tell under circumstances like these just what would happen. "If we could only get into the air-lock we would be farther away from the explosion and less likely of being bashed up," said Jay as he looked toward the exit chamber. "Yes, and if we could get into the air-lock we could get out into the access tube," added Dick. Steadily they gazed into each other's eyes. Jay held his own watch in his hand, while Dick at intervals looked at the tiny steel clock behind a wire socket on the side of the _Nautilus_. By the rays of an incandescent bulb Dick could see that the minute hand had just turned twenty-seven minutes after one o'clock. Tick by tick the clock was measuring off the few seconds that remained until the time bomb in the coal bunker underneath was scheduled to go off. Like two men sentenced to die before an enemy firing squad the Brighton lads stood facing each other in the diving compartment. Just the trace of a smile showed over their faces. They clenched hands in a firm grasp. "In half a minute more----"