Page:Tom Swift and His Giant Cannon.djvu/46

36 one of the boxes open. Reaching into the depths he held up a handful of something that looked like sticks of macaroni. "There it is," he said.

"That powder?" cried Ned. "That's a queer kind. I've seen the kind they use in some guns on the battleships. That powder was in hexagonal form, about two inches across, and had a hole in the centre. It was colored brown."

"Well, powder is made in many forms," explained Tom. "A person who has only seen black gunpowder, with its little grains, would not believe that this was one grain of the new powder."

"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