"That's what I hope it will prove to be—and powerful powder at that."
"Why, it looks more like excelsior than anything else," went on the odd man, gingerly taking up some yellowish shreds in his fingers.
"And it will burn as harmlessly as excelsior in the open air," went on Tom. "But I hope to prove, when it is confined in a chamber, that it will be highly explosive. I'm going to make a test of it soon."
"Give me good notice, so I can get over in the next State!" exclaimed Ned Newton, with a laugh.
This was several days after our friends had returned from the disastrous gun test at Sandy Hook. Tom had at once gotten to work on the problem that confronted him—a problem of his own making—to build a giant cannon that would make the longest shots on record. And he had first turned his attention to the powder, or explosive, to be used.
"For," he said, "there is no use having a big gun unless you can fire it. And the gun I am planning will need something more powerful in the powder line than any I've ever heard of."
"Stronger than the kind General Waller used?" inquired Ned.
"Yes, but I'll make my cannon correspondingly stronger, too, so there will be no danger."
"Bless my shoe buttons!" exclaimed Mr. Damon. "You boys must have had your nerve with you to stay around Sandy Hook after that gun went up in the air."
"Oh, the danger was all over soon after it began," spoke Tom, with a smile. "But now I'm going to test some of this powder. If you want to run away, Mr. Damon, I'll have Koku take you up in one of the airships, and you'll certainly be safe a mile or so in the air," for Tom had instructed his giant servant how to run one of the simpler biplanes.