A tramp of heavy feet on the deck proved that those outside the shell had heard the noise and were rushing toward the conning-tower hatch.

Bob, without pausing an instant, darted through the door and dropped down the hatch leading to the tank room and the motor room.


CHAPTER XXXVII.
OFF FOR THE AMAZON.

Bob Steele considered himself personally responsible for the safety of the Grampus. The boat had been placed in his charge by Captain Nemo, junior, her owner, and the captain’s faith in the boys was unlimited. Bob was to take the submarine to Mare Island Navy Yard and collect one hundred thousand dollars for her from the government. Those were his instructions, and the captain not only expected them to be carried out to the letter, but he also expected to pay Bob Steele well for doing it.

All this responsibility, it may be, had got on Bob’s nerves a little, so that he was apt to shy at imaginary dangers. But this fact in no wise interfered with his coolness and courage.

The whole under part of the submarine’s hull was filled with smoke—a smoke that had the acrid smell of burned gas. On hands and knees, Bob groped his way through the haze, pulled a switch, and set an electric ventilator fan at work. The fan soon cleared the ship, and the first figure Bob saw was that of the gasping Chinaman. He was on his knees in the tank room. In front of him lay a twisted and broken gasoline tank—a small reserve reservoir sometimes used to help out the larger tank when the fuel in it was running low. This auxiliary tank had not been used for a month, but had hung empty from a rack in the tank room.

At the Chinaman’s side lay a cigarette and a half-burned match.

“What the deuce happened?” cried Glennie, creeping after Bob.