The Lieutenant lifted a hand for silence.
From outside, seemingly from underneath the keel of the Sea Lion, came a grating sound, which was followed by a slight, though steady, lifting of the vessel.
"Gee!" cried Jimmie, springing to his feet. "I guess we're up against an earthquake!"
The boys were all moving about now, but Lieutenant Scott remained in his chair, a smile on his face.
The Sea Lion rose steadily, and there was a slight tip to port. Ned sat down with a shamed look on his face.
"I should have known," he said.
"Say," Jack exclaimed, "was the submarine put together on the float that is going to carry her across?"
"Of course she was," laughed the Lieutenant. "The pieces brought on from New York were assembled on the float. Some of the larger pieces, the ones most difficult to handle, were made here from patterns sent on from the east. Then, when all was ready, the float was dropped out of sight so the submarine would lie on the surface, as we found her."
"And now they're lifting the float?" asked Jimmie.
"Exactly," was the reply. "Suppose you go outside, on the conning tower, and look about."