“Come, father,” said Rollo again; “we’re all ready.”
Rollo returned into the kitchen, and his father followed him. His mother came, too, for she wanted to see them make the gunpowder. Jonas asked Mr. Holiday if he should want a pair of scales.
“No,” said he, “we can guess at the proportions near enough. We can’t expect to make very good gunpowder.”
“Why not, sir?” said Rollo; “the things are all good that we are going to make it of.”
“Very likely,” said his father; “but we cannot make them fine enough,—nor mix them intimately.”
“Why, father,” said Rollo, “Jonas has made them very fine indeed.”
“Yes, I have no doubt that he has pulverized them as well as it can be done in a mortar. But it is not possible to make them as fine in that way as they do in the powder-mills. Then, to mix them properly, they ought to be wet and ground together a long time. We can’t stop to do that.
“And now, first,” he continued, “I want you all to observe how these various materials will burn by themselves, and then see how differently they will burn together.”
Mr. Holiday then took up a coal of fire, and put it upon the shovel; and he asked Jonas to hold it for him in the fireplace, under the throat of the chimney, so that the smoke and fumes might not come out into the room. He then took from the cup which had the sulphur in it, a little of the sulphur upon the point of his knife, and laid it down gently upon the coal of fire. It burned with a very small and faint blue flame. It burned very slowly, and the flame continued for some time; but the flame was not much bigger than the sulphur itself which caused it.
He then tried the same experiment with the saltpetre. The effect was very different, though in this case there was scarcely any flame. It made a little faint flash, accompanied with a slight crackling sound. Then he tried the charcoal, but it did not appear to burn at all. It lay in a little black heap upon the burning coal, just as Mr. Holiday put it on. After a time, however, it began to grow red upon the under side, and finally became red throughout; and then it could hardly be distinguished in appearance from the coal which it was lying upon.
“So you see,” said Mr. Holiday, “that these three ingredients are not very combustible by themselves; at least, they burn very quietly, and with very little flame. Now, we will mix them together. We want a tea-spoon Dorothy.”