"What are they?" asked Jack.
"Electric guns," replied the professor. "But come on now, we have no time to lose."
Further conversation was impossible, for the boys had their heavy copper helmets on, and they were as tightly enclosed as if inside a box. They grasped their weapons and waited for the next move.
The professor led the way to the stern of the ship. The boys found it hard to walk, as they were weighted down by the heavy suits, and also the boots, the soles of which were of lead.
They followed the inventor into what seemed a small room. Inside they found themselves in darkness. There was a clanking sound as Washington fastened and clamped the door shut. Then came a hissing.
The boys felt water rising about them. They could experience its coldness, even through the diving suits. They were much afraid, but the professor put a reassuring hand on their shoulders.
They seemed to feel a great weight. It gradually lessened, however, and, in a few minutes, they saw something move in front of them. The professor pushed them gently forward.
In another instant they were walking on the bed of the ocean, having stepped from the Porpoise. They had gone into a locked compartment, the inner door of which had been tightly closed, after which water from outside had been gradually admitted until the pressure was equal, and then the boys and the professor had merely to emerge out into the bottom of the sea when the outer portal was swung aside by Washington, who worked the lever from inside.
The boys were in intense darkness, but, suddenly a light glowed about them, and they saw that the professor had switched on his miniature search lamp. They remembered how he had told them to work the apparatus, and soon tiny gleams shot out from their helmets.
The professor pointed ahead, for not a sound could be heard, and the boys followed him.