"Well, you know the prevailing wind in winter is from the west. Why shouldn't our men start relays of light balloons——"
"Balloons always are light."
"I mean light-giving balloons. They'd float over the German lines and illuminate their whole positions with a steady continuous light."
"The Huns would shoot 'em down."
"Not easily, for they'd be dark."
"Light and dark at the same time! Go on, Bobby; I'm sure you can prove black's white."
"If you wouldn't interrupt, you'd see. The illuminant would be attached to the balloon by a long cord, and there'd be a shade like a lampshade over it, so that the balloon itself would be in darkness. It's easy enough to try."
"How?"
"All you want is a dozen toy balloons, a few cubic feet of hydrogen, a slow match, and a little magnesium wire. There you have it on a small scale. Fill the balloons with hydrogen, tie 'em together, fasten a slow match and a bit of wire to each, light the match, and send the whole caboodle up."
"But magnesium wire only burns for a second or two."