Here Miss Turner stopped and said: "Next Saturday, if it is pleasant, we will have our annual spring picnic. We will go to a new place this time. We will try Howland's Grove, and then in the afternoon we will go down into the Jefferson mine and see what it is like."
We have not time to read about the picnic, nor of the interest that the class showed before the appointed Saturday, as well as all the forenoon of that day. Nor can we tell how the children went down the shaft of the mine, and how they were at first so quiet that hardly a word was said. The teacher showed them a layer of coal in the mine which was about three feet thick. Just above it was a rock which was different from the coal. This they were told was sandstone, the hardened sand which had been heaped upon the forests so many thousand years before. Then below the coal was another rock which was entirely unlike either the coal or the sandstone. This was the seat-stone, the rock made out of the soil in which the forest had grown. Then below this they found three more layers, sandstone, coal, and seat-stone, and so on until the bottom of the mine was reached.
By this time the children were ready to ask questions.
"Oh, Miss Turner, what is this curious-looking thing in this part of the seat-stone?" asked one of the boys.
Miss Turner replied: "That is a fossil. It is part of a root of a tree, and has retained its shape and appearance all these thousands and thousands of years."
One of the miners who had been listening to the conversation said: "If you will step this way, madam, I can show you the whole of a tree-trunk in the coal."
The children eagerly crowded around as the miner showed the fossilized trunk of a tree still standing just as it grew, with its roots in the seat-stone and its top in the sandstone above the coal--for here the layer of coal was several feet in thickness.
A few minutes afterward, as the children were looking carefully at the sides of the mine to see if they could find more fossils, the shy little girl said quietly to the teacher: "I think that I have found something, Miss Turner; won't you please see?"
She led the way to a trunk which showed the various stages in the process of change. One end was still almost like wood, the middle part was a very soft brown coal, while the other end was true coal.