human
What’s up, old man? asked Eves, who was already in bed.
gpt
Got toothache?
human
No; I was thinking, replied Templeton, rubbing again.
gpt
You see——
human
But I can’t hear through the bristles. Hurry up, or I shall be asleep.
gpt
Those flash-lights, you know—they don’t last long enough. What our fellows want is some continuous illumination.
human
What about the moon?
gpt
You know perfectly well the moon doesn’t shine for half the month.
human
I thought perhaps you’d invented an artificial moon. But expound, old bird.
gpt
Well, you know the prevailing wind in winter is from the west. Why shouldn’t our men start relays of light balloons——
human
Balloons always are light.
gpt
I mean light-giving balloons. They’d float over the German lines and illuminate their whole positions with a steady continuous light.
human
The Huns would shoot ’em down.
gpt
Not easily, for they’d be dark.
human
Light and dark at the same time! Go on, Bobby; I’m sure you can prove black’s white.
gpt
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.
human
How?
gpt
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.
human
But magnesium wire only burns for a second or two.
gpt
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.
human
You mean to try it, then?
gpt
Of course. Old Noakes has some toy balloons.
human
But what about the hydrogen? It doesn’t smell, does it?
gpt
No. Why?
human
Only that I forget all my chemistry except the stinks. How do you make it?
gpt
By the action of an acid on a metal. Don’t you remember Zn + H2SO4 = ZnSO4 + H2? Iron will do as well.
human
That’s easy enough, then. But you’ll want retorts, wash bottles, pneumatic troughs, and goodness knows what else. Bang goes the rest of your cash, Bob.
gpt
Nonsense! Mother Trenchard has some old pickle bottles, and we’re not out to make a specially pure gas. All we’ll have to buy will be a little acid, a few feet of glass tubing, and a rubber cork or two. Four or five shillings will buy the lot. We shall have to go to Weymouth for them.
human
Righto! That’s a day off to-morrow.