Templeton, meanwhile, had been anxiously weighing the claims of the other ideas that jostled in his brain. He wanted to perfect his automatic hair-cutter; to experiment with what he called, in advance, a "levitator"—a contrivance for enabling an aeroplane to rise more rapidly; to test his notion of a tar entanglement, and various other sound schemes. Unfortunately the incomplete hair-cutter had been confiscated by his head master, and it would take weeks to construct a new one. The levitator was out of the question at present, for it would cost a good deal more than the two pounds odd which remained out of his aunt’s gift. Several ideas were unworkable for the same reason, and he had almost resolved on the tar entanglement when, with that suddenness to which inventors are accustomed, a quite new idea shot into his mind. He had been reading, in a war correspondent’s dispatch, about the star shells and Verey lights which were used at night to throw a fitful illumination upon the hostile lines. Eves noticed that as he cleaned his teeth before going to bed he made frequent pauses, holding the tooth-brush motionless for some moments at a time. "What’s up, old man?" asked Eves, who was already in bed. "Got toothache?" "No; I was thinking," replied Templeton, rubbing again. "You see——" "But I can’t hear through the bristles. Hurry up, or I shall be asleep." Templeton finished his toilet, blew out the light, and got into bed, sitting up and clasping his knees. "Those flash-lights, you know—they don’t last long enough. What our fellows want is some continuous illumination." "What about the moon?" "You know perfectly well the moon doesn’t shine for half the month." "I thought perhaps you’d invented an artificial moon. But expound, old bird." "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." "You really are an ass, Tom. We’d only use magnesium wire for our experiment; there are heaps of things that could be used with big balloons at the front."