"To-morrow," Jimmie said, "you can take a run on the riparian rights an' chase whales."

"I'll wait and see whether you boys come out alive," laughed Frank. "I'm a little leary about mixing with the funny little fishes. Some of 'em may bite!"

After a thoroughly interesting voyage, the boys had at last reached the scene of their labors. It was now the 20th of October. The Sea Lion had rode securely on the float, and Ned and his companions had spent most of the time during the journey under the great hood which covered the submarine, studying the mechanism and making themselves thoroughly familiar with the big machine.

Arriving off the Taya Islands, the float had been submerged by opening the sluiceways and filling the tanks with water. The Sea Lion behaved admirably when she came to the surface after cutting away from the companion of her voyage.

As there were no appliances for lifting the big float, she was now at the bottom of the sea for all time, unless broken away from the water-filled tanks by divers, in which case the upper works would come to the surface. It was with feelings of keen regret that the boys saw the great barge, as it might well be called, lying, deserted, on the ocean floor.

As has been shown by the conversation between the boys in the conning tower, Lieutenant Scott had fully recovered from the effects of the poisonous fumes he had inhaled in the submarine on the night of Ned's arrest at South Vallejo. Physicians stated at the time that his recovery was due to the fact that the conning tower hatch was open when the deadly gas was released. Ned, it was also stated, would have been dead in a few moments if the hatch had been closed.

Search had been made, both by the police and the naval detectives, for the author of the mischief, but he had not been found. It was believed that his purpose in reporting the result of his own deviltry to the chief of police was to secure the arrest of the boys on the Sea Lion and make off with her.

Ned did not say so, when discussing the matter with the officers, but he was satisfied that the Moores were at the bottom of the trouble. The Captain had resigned, and had been observed lounging about the wharf in New York where the Sea Lion lay, and had, it was afterwards learned, been seen in San Francisco on the day before the arrival of Lieutenant Scott and the Boy Scouts.

In reaching this conclusion Ned assigned envy as the prime motive on the part of the Captain and his son. They had expected to be assigned the duty of searching the ocean floor for the wreck of the mail steamer. In their great disappointment nothing was more probable than that they had resolved to hamper the efforts of their successful rivals in every way.

But there was still another view of the case which might be considered. The gold in the hull of the wrecked steamer would become the spoil of the first submarine to reach her.