Chapter Eleven. On the Ocean Bed

Lower and lower sank the submarine. There was a swirling and foaming of the water as she went down, caused by the air bubbles which the craft carried with her in her descent. Only the top of the conning tower was out of water now, the ocean having closed over the deck and the rounded back of the boat. Had any one been watching they would have imagined that an accident was taking place.

In the pilot house, with its thick glass windows, Tom, his father and Captain Weston looked over the surface of the ocean, which every minute was coming nearer and nearer to them.

"We'll be all under in a few seconds," spoke Tom in a solemn voice, as he listened to the water hissing into the tanks.

"Yes, and then we can see what sort of progress we will make," added Mr. Swift. "Everything is going fine, though," he went on cheerfully. "I believe I have a good boat."

"There is no doubt of it in my mind," remarked Captain Weston, and Tom felt a little disappointed that the sailor did not shout out some such expression as "Shiver my timbers!" or "Keel-haul the main braces, there, you lubber!" But Captain Weston was not that kind of a sailor, though his usually quiet demeanor could be quickly dropped on necessity, as Tom learned later.

A few minutes more and the waters closed over the top of the conning tower. The Advance was completely submerged. Through the thick glass windows of the pilot house the occupants looked out into the greenish water that swirled about them; but it could not enter. Then, as the boat went lower, the light from above gradually died out, and the semi-darkness gave place to gloom.

"Turn on the electrics and the searchlight, Tom," directed his father.

There was the click of a switch, and the conning tower was flooded with light. But as this had the effect of preventing the three from peering out into the water, just as one in a lighted room cannot look out into the night, Tom shut them off and switched on the great searchlight. This projected its powerful beams straight ahead and there, under the ocean, was a pathway of illumination for the treasure- seekers.

"Fine!" cried Captain Weston, with more enthusiasm than he had yet manifested. "That's great, if you don't mind me mentioning it. How deep are we?"

Tom glanced at a gage on the side of the pilot tower.

"Only about sixty feet," he answered.

"Then don't go any deeper!" cried the captain hastily. "I know these waters around here, and that's about all the depth you've got. You'll be on the bottom in a minute."

"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.