"I intend to get on the bottom after a while," said Mr. Swift, "but not here. I want to try for a greater distance under water before I come to rest on the ocean's bed. But I think we are deep enough for a test. Tom, close the tank intake pipes and we'll see how the Advance will progress when fully submerged."

The hissing stopped, and then, wishing to see how the motors and other machinery would work, the aged inventor and his son, accompanied by Captain Weston, descended from the conning tower, by means of an inner stairway, to the interior of the ship. The submarine could be steered and managed from below or above. She was now floating about sixty-five feet below the surface of the bay.

"Well, how do you like it?" asked Tom of Mr. Damon, as he saw his friend in an easy chair in the living-room or main cabin of the craft, looking out of one of the plate-glass windows on the side.

"Bless my spectacles, it's the most wonderful thing I ever dreamed of!" cried the queer character, as he peered at the mass of water before him. "To think that I'm away down under the surface, and yet as dry as a bone. Bless my necktie, but it's great! What are we going to do now?"

"Go forward," replied the young inventor.

"Perhaps I had better make an observation," suggested Captain Weston, taking his telescope from under his arm, where he had carried it since entering the craft, and opening it. "We may run afoul of something, if you don't mind me mentioning such a disagreeable subject." Then, as he thought of the impossibility of using his glass under water, he closed it.

"I shall have little use for this here, I'm afraid," he remarked with a smile. "Well, there's some consolation. We're not likely to meet many ships in this part of the ocean. Other vessels are fond enough of remaining on the surface. I fancy we shall have the depths to ourselves, unless we meet a Government submarine, and they are hardly able to go as deep as we can. No, I guess we won't run into anything and I can put this glass away."

"Unless we run into Berg and his crowd," suggested Tom in a low voice.

"Ha! ha!" laughed Captain Weston, for he did not want Mr. Swift to worry over the unscrupulous agent. "No, I don't believe we'll meet them, Tom. I guess Berg is trying to work out the longitude and latitude I gave him. I wish I could see his face when he realizes that he's been deceived by that fake map."

"Well, I hope he doesn't discover it too soon and trail us," went on the lad. "But they're going to start the machinery now. I suppose you and I had better take charge of the steering of the craft. Dad will want to be in the engine-room."