Daughter. Why, yes, mother; that is what the fire is made for. We feel cold, and we want a fire to make us warm; and when the fire is made, it sends out heat, and makes us warm.
Mother. Well, now, where can the heat come from? You know what fire is made from, do you not?
Daughter. Certainly, mother; the fire is made of wood, or of coal.
Mother. But is the wood or the coal warm before the fire is made?
Daughter. No, mother, the wood and the coal come from the cold wood-house, or the cellar, and they are both very cold.
Mother. And yet, the wood and the coal become very hot when they are on fire.
Daughter. O yes, mother, so hot that we cannot touch them with our hands, and we have to take the shovel or the tongs to move them.
Mother. And do they burn the shovel and the tongs, my dear?
Daughter. Why, no, mother; if they did, the shovel and the tongs would be of little use in stirring the fire.
Mother. Can you think of any reason why they do not burn the shovel and the tongs?
Daughter. You told me, mother, that some things require a very little heat to set them on fire, and that other things require a great deal. I suppose that there was not heat enough to set them on fire; and if there had been, they would not burn, because they are made of iron.
Mother. You are partly right, my dear, and partly wrong. They would not burn, because there was not heat enough in the fire to burn them. But there are very few things, and in fact it may be doubted whether there is anything, which will not burn, when sufficient heat is applied. But let us return to the fire: you say the heat does not come from the windows nor from the chimney, and you say, also, that the wood and the coal are both cold. Now, where can the heat come from?
Daughter. I am sure I cannot tell, mother; will you please to tell me?
Mother. You recollect that I told you that the rubbing of the match on the sand-paper produces a little heat, which caused the match to burn. The match was then applied to the shavings, and, as it was burning, gave out heat enough to set the shavings on fire; the shavings produced heat enough to set the pine wood, or kindling, on fire, and then the pine wood, or kindling, produced more heat, and set the wood and coal on fire. Now, there was nothing to produce the heat but the match, the shavings, the wood and the coal; and the heat must have been in them. The fire only served to set it free, and let it come out of the match, the wood, and the coal.
Daughter. But, mother, how did the heat get into the wood and coal?
Mother. It is not known, my dear, how the heat got into the wood and coal, any more than how the fruit gets on to a tree. We say that it grows on the tree; but what growing is, and how it is caused, are among the secrets of God.