"That macaroni stick a grain of powder?" cried Ned.
"Yes, we'll call it a grain," went on the young inventor, "just as the brown, hexagonal cube you saw was a grain. You see, Ned, the idea is to explode all the powder at once—to get instantaneous action. It must all burn up at once as soon as it is detonated, or set off.
"To do that you have to have every grain acted on at the same moment, and that could not be done if the powder was in one solid chunk, or closely packed. For that reason they make it in different shapes, so it will lie loose in the firing chamber, just as a lot of jack-straws are piled up. In fact, some of the new powder looks like jack-straws. Some, as this, for instance, looks like macaroni. Other is in cubes, and some in long strings."
As he spoke Tom struck a match and held the flames near the end of one of the "macaroni" sticks.
"Caesar's grandmother!" yelled Ned. "Are you crazy, Tom?" as he started to leap for a window.
"Don't get excited," spoke Tom, quietly. "There's no danger," and he actually set fire to the stick of queer powder, which burned like some wax taper.
"But—but—" stammered Ned.
"It is only when powder is confined that it explodes," Tom explained. "If it can burn in the open it's as harmless as water, provided you don't burn too much at once. But put it in something where the resulting gases accumulate and can't escape, and then—why, you have an explosion—that's all."
"Yes—that's all," remarked Ned, grimly, as he nervously watched the burning stick of powder. Tom let it flame for a few seconds, and then calmly blew it out.
"You know what a little puff black gunpowder gives, if you burn some openly on the ground," went on Tom; "don't you, Ned?"