her._ Now rub them together quickly a little while, and then touch
them to your cheek.

[Illustration: R]

_Daughter._ O, dear, mother! they are so hot that they almost burnt my
cheek.

_Mother._ Yes, Caroline; and do you not recollect, when you read
Robinson Crusoe, that his man Friday made a fire by rubbing two pieces
of wood together?

_Daughter._ O, yes, dear mother; and I have often wondered why Alice
could not light her lire and the lamp in the same manner, without those
matches, which have so offensive a smell.

_Mother._ It is very hard work, my dear, to obtain fire by rubbing two
pieces of wood together; and it would take too long a time to do it. The
two pieces of wood would grow warm by a very little rubbing; but in
order to make them take fire, they must be rubbed together a great
while.

_Daughter._ But, mother, if it takes so long a time to get fire by
rubbing two pieces of wood together, why can Alice set the match on fire
so easily by rubbing it once on the sand-paper?

_Mother._ That is what I am about to explain to you, my dear. Here, take
this piece of paper and hold it up to the lamp.

_Daughter._ It has taken fire, mother.

[Illustration: L]

_Mother._ Now take this piece of pine wood, and hold that up to the lamp
in the same manner, and see whether that will take fire too.

_Daughter._ Yes, mother, it has taken fire; but I had to hold it up to
the lamp much longer than I did the paper.

_Mother._ Now take this piece of hard wood, and do the same with that.

_Daughter._ The hard wood takes longer still to catch fire, mother.

_Mother._ Yes, my child. And now I am going to make the hard wood take
fire more quickly than the paper did.

_Daughter._ Dear mother, how can you do it?

_Mother._ I am going to show you, my dear. Here is a small phial, which
contains something that looks like water. It is spirits of turpentine. I
shall dip the point of the piece of hard wood into the phial, and take
up a little of the spirits of turpentine. Now, Caroline, touch the point
of the hard wood with the turpentine on it to the flame.

_Daughter._ Why, mother, it caught fire as soon as I touched the flame
with it!

_Mother._ Yes, certainly; and you now see that some things, like the
spirits of turpentine and the paper, take fire very readily, and others
take fire with more difficulty.

_Daughter._ Yes, mother; but when Alice drew the match across the
sand-paper, there was no flame nor fire to