the shop; but be careful where you put it."

"I do, Master," replied the giant.

"What sort of powder is that, Tom?" asked Ned a little later,
when they were again back in the office, the excitement having
calmed down. The expressman had gone back to town afoot, to
arrange about getting another vehicle for what remained of his
load. "Is it the kind they use in big guns?"

"One of the kinds," replied Tom. "I sent for several samples,
and this is one. I'm going to conduct some tests to see what kind
I'll need for my own big gun. But I expect I'll have to invent an
explosive as well as a cannon, for I want the most powerful I can
get. Want to look at some of this powder?"

"Yes, if you think it's safe."

"Oh, it's safe enough if you treat it right. I'll show you,"
and working carefully Tom soon had 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