He and James went to the shed, and selected some pieces of wood, which Rollo said would be suitable for their charcoal bed. He put them into a small saw-horse, which Jonas had made for him to saw wood in, and without much difficulty he sawed a sufficient quantity. James put the sticks into Rollo’s little wheelbarrow as fast as they were sawed. It was not very long before the wheelbarrow was filled nearly full.
“Come, Rollo,” said James; “here is enough.”
“No,” said Rollo; “let us fill the wheelbarrow full.”
“Why, Rollo,” said James, “you’ve got enough already to make a barrel of gunpowder.”
“O, it won’t all come into gunpowder,” said Rollo; “some of the wood will burn up, I expect. You see we are going to have slow combustion.”
“Slow what?” said James.
“Slow combustion,” replied Rollo; “don’t you know what combustion means?”
“No,” said James.
“It means burning; that is, one kind of burning. You see there are a great many kinds of burning. Combustion is when it burns all up. If you put your finger in the fire and burn it, it doesn’t burn up, does it?”
“I suppose it would, if I held it in long enough,” said James.