An official inquiry was at once started, and, while it would take some time to complete it (for the parts of the gun remaining were to be subjected to an exhaustive test to determine the cause of the weakness), it was found that there was some defect in the wiring and battery that was used to fire the charge.
The soldier who was to press the button was sure he had not done so, as he had been ordered to wait until General Waller gave the signal from the bomb-proof. But the gun went off before its inventor reached that place of safety. Just what had caused the premature discharge could never be learned, as part of the firing apparatus had been blown to atoms.
"Well, Tom, what do you think of it?" asked Ned, who had now fully recovered from the shock. The two were about to leave the proving grounds, having seen all that they cared to.
"I don't know just what to think," was the answer. "It sure was a big explosion, and it goes to prove that, no matter how many calculations you make, when you try a new powder in a new gun you don't know what's going to happen, until after it has happened—and then it's too late. It's a big problem, Ned."
"Do you think you can solve it? Are you still going on with your plan to build the biggest cannon ever made?"
"I sure am, Ned, though I don't know that I'll make out any better than General Waller did. It's too bad his was a failure; but I think I see where he made some mistakes."
"Oh, you do; eh?" suddenly exclaimed a voice, and from a nearby parapet, where he had gone to look at one of the pieces of his gun, stepped General Waller. "So you think I made some mistakes, Tom Swift? Where, pray?"
"In making the breech. The steel jackets were of uneven thickness, making the strain unequal. Then, too, I do not think the powder was sufficiently tested. It was probably of uneven strength. That is only my opinion, sir."
"Well, you are rather young to give opinions to men who have devoted almost all their lives to the study of high explosives."
"I realize that, sir; but you asked me for my opinion. I shall hope to profit by your mistakes, too. That is one reason I wanted to see this test."