1. Next day the children asked their mother to tell them what coal
really was. Harry did not think it was a stone, because he had broken
two or three lumps with a hammer. He found that it broke much more
easily than stone.

2. Besides, it did not fly all into sharp bits, but came off in slices;
and he saw that it had straight lines along it. When he poked his knife
in between these lines, he could take off a slice of coal at once!

3. Dora did not think it was a metal, because she had learnt that iron
would melt in a fire and flow like water. 'Coal does not melt,' she
said, 'every one knows that!'

4. She took a small lump out of the coal-box, and Harry did the same.
Mother then fetched some pictures, and one or two other things, and the
talk began.

5. 'It is no wonder that you can't guess what coal is! It does not look
at all like what it was at first. It was not always in the ground; it
used to live on the top and get the air and sunshine.'

6. 'It must have been alive,' said Harry. 'Was it an animal?'

'No.'

'Then it was a plant!' cried Dora.

7. 'Well, it is all that is left of many plants and trees, whole forests
of plants and trees, that grew long, long ago.'