“I don’t know of any way.”
“Couldn’t we put it on the end of the wick?” asked Rollo.
“Yes,” said his father, “perhaps we might; but then the end of the wick is cool, and that would cool it.”
“O, father,” said Rollo, in a tone of great surprise, “the end of the wick cool, when it is right in the middle of the blaze!”
“I mean,” replied his father, “that it is cool compared with the heat necessary for inflaming the iron. It would feel very hot to your fingers, I have no doubt, for it is filled with boiling oil. But then even the heat of boiling oil is less than that necessary to inflame iron; and so the contact of the wick with such a piece of iron as you propose, would keep it cool, or rather keep it from getting hot enough to take fire.”
“Suppose there was any way,” said Rollo’s mother, “of suspending a piece of iron as large as the end of a knitting-needle in the lamp; do you think it would take fire?”
“No,” said Mr. Holiday, “I don’t think it would be heated hot enough. For some reason or other, I don’t understand exactly what, a large piece of iron cannot be heated very hot in a small fire, even if the fire entirely covers it. I don’t think that any fragment of iron much larger than one of Jonas’s filings could be heated in a lamp so as to take fire. But it could be heated hot enough in a forge. The end of the iron which a blacksmith heats is often in a state of combustion when he takes it out of the fire.”
“There, now, father,” said Rollo, “you have not explained to me yet about combustion and burning.”
“No,” said his father; “we had almost forgotten that. I will explain it now. It will only take a few minutes. Let me see—I began to tell you didn’t I?”
“Yes, sir,” said Rollo; “but I couldn’t understand very well.”