“What is it, Fitz?”
“Magnetic powder.”
“There’s a bottle of it in the locker; I saw it there this morning. But what on earth are you going to do with it?”
“I’ll tell you. I’m going to sprinkle some of it in the spring; and it’ll magnetize the water. Then any animal that comes for a drink will get a shock that will stir up its ideas—and send it flying. Won’t that be great?”
“Great?” Bob cried, capering about in glee. “Yes, indeed, Fitz! And won’t it be funny to hear ’em and see ’em? I’m not a bit sleepy now. Let’s fix the spring right now.”
Soon they had magnetized the spring, and had snuggled down in the car of their balloon, to spend the night. By that time it was quite dark; so they partook of a few food-tablets and drink-pellets, and then composed themselves to rest—out of reach of any beast that might come prowling around. Bob dropped into a doze. A roar like distant, muttering thunder roused him. He sat up and rubbed his eyes; then he nudged his sleeping companion.
“Huh!” ejaculated Fitz, waking with a start.
“I heard something roaring—sounded like thunder,” the boy explained.
“Where?”
“I don’t know; I wasn’t wide enough awake to tell. There—there it goes again.”