be blown off our course. We have air enough to stay below, haven't we, Tom?"
"Plenty," answered the lad, looking at the gages.
After a hearty breakfast the next morning, the submarine crew got ready for their hard task. The craft was backed away as far as was practical, and then, running at full speed, she rammed the wreck. The shock was terrific, and at first it was feared some damage had been done to the Advance, but she stood the strain.
"Did we open up much of a hole?" anxiously asked Mr. Swift.
"Pretty good," replied Tom, observing it through the conning tower bull's-eyes, when the submarine had backed off again. "Let's give her another."
Once more the great steel ram hit into the side of the Boldero, and again the submarine shivered from the shock. But there was a bigger hole in the wreck now, and after Captain Weston had viewed it he decided it was large enough to allow a person to enter and place a charge of dynamite so that the treasure ship would be broken up.
Tom and the captain placed the explosive. Then the Advance was withdrawn to a safe distance. There was a dull rumble, a great swirling of the water, which was made murky; but
