Part 5 (1/2)

”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 ases accumulate and can't escape, and then--why, you have an explosion--that's all”

”Yes--that's all,” re stick of powder Tom let it flame for a few seconds, and then calunpowder gives, if you burn soround,” went on Tom; ”don't you, Ned?”

”Sure, I've often done that”

”But put that saht box, and set fire to it, and you have a bang instead of a puff It's the same ith this powder, only it doesn't even puff, for it burns more slowly

”An explosion, you see, is the sudden liberation at one tiases which result when the powder is burned If the gases are given off gradually, and in the open, no harm is done But put a stick like this in, say, a steel box, all closed up, save a hole for the fuse, and what do you have? An explosion That's the principle of all guns and cannon

”But say, Ned, I'ular lecturer I didn't knoas running on so Why didn't you stop me?”

”Because I was interested Go on, tell et this powder in a safe place I'm a little nervous about it after that fire You see if it had caught, when tightly packed in the boxes, there would have been a terrific explosion, though it does burn so harmlessly in the open air Now let me see--”

Tom was interrupted by the postman's whistle, and a little later Eradicate came in with the mail that had been left in the box at the shop door Tom rapidly looked over the letters

”Here's the note I want, I think,” he said, Selecting one ”Yes, this is it 'Perranted,' he read, 'to Thomas Swift to visit,' and so on, and so on This is the stuff, Ned!” he cried

”What is it?”

”A perrounds at Sandy Hook, Ned, and see 'e you about Hurray!

We'll go down there, and I'll see how overno down, Too with ht very uess I will When is it?”

”A week froet ready

Now let's get busy, and we'll arrange to go to Sandy Hook I've had trouble enough to get this peret lost,” and he locked it in a secret drawer of his desk

Then the lads stored the powder in a safe place, and soon were busy about several matters in the shop

CHAPTER V

OFF TO SANDY HOOK