"Do you imagine, then, Mr. Benson, that some of the naval machinists have been careless or incompetent?"
"Why, that would be a wild guess to make, sir, when one, remembers what high rank your naval machinists take in their work," Jack Benson replied.
"And this boat was sold to the Navy with the strongest guarantee for the engines," pursued the officer in charge.
Jack and Hal were both worried. The sudden break had a bad look for the Pollard boats, in the success of which these submarine boys were most vitally interested.
At last, from below, the suspected parts of the engine were reported to be cool enough for examination. The naval officer in charge followed Jack and Hal below.
Taking off his uniform blouse and rolling up his sleeves, Hal sailed in vigorously to locate the fault. Machinists and cadets stood about, passing him the tools he needed, and helping him when required.
At last, after disconnecting some parts, Hal drew out a long, slender brass piston.
As he held it up young Hastings's face went as white as chalk.
"Do you see this?" he demanded, hoarsely.
"Filed, crazily, and it also looks as though the inner end had been heated and tampered with," gasped Jack Benson.