"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."
"You mean to try it, then?"
"Of course. Old Noakes has some toy balloons."
"But what about the hydrogen? It doesn't smell, does it?"
"No. Why?"
"Only that I forget all my chemistry except the stinks. How do you make it?"
"By the action of an acid on a metal. Don't you remember Zn + H2SO4 = ZnSO4 + H2? Iron will do as well."
"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."
"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."
"Righto! That's a day off to-morrow."