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"I have been thinking over our chat about things that burn," said Norah. "Why, Fred, we left out coal, and we all know coal is a good thing to burn. We use it to make our fires.""Yes, sister," said Fred. "We use coal for fuel, to make our fires. But teacher says there is so much to learn about coal, that we must take it by itself.
"Go and get a piece of coal, Willie. We will find out all we can about it.
"Now, Norah," he went on, "take the coal in your hand. What can you learn by looking at it?""It is black and shiny," said Norah. "It looks like a lump of smooth, shiny hard, black stone.""Quite right," said Fred. "Now hit the coal with this hammer, and you will see that it easily breaks up into pieces.""So it does." said his sister. "It is brittle, as well as hard.""Now look at your hands, you dirty girl.""Oh dear," said Norah, "the dirty coal has made me quite black. The black comes off on my hands."Fred next took the piece of coal up with the tongs, and held it in the flame of the fire. It soon caught fire, and burst out in a bright flame.
"That"s just what I meant, Fred," said Norah. "Coal is one of the best things to burn. It burns till it is all gone. It gives out great heat while it burns.""Yes," said Fred, "that is why we use it for fuel." "I should like to know where we get coal from,"said Norah.
"Well then," said Fred, "I"ll soon tell you. Coal is a mineral, like stone, chalk, marble, rock-salt, clay, sand, and gravel. It is dug out of the ground.
"Men dig great deep holes in the ground to get the coal," he added. "We call the holes mines. The men who dig the mines are called miners."SUMMARY
Coal is dug out of the ground, like stone, clay, chalk, and rock-salt. We call it a mineral; the great deep hole in the earth, where the men dig it up, is a mine; the men who dig it are miners. We use coal for fuel, because it burns well, and gives out great heat.
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"You know," said Fred, "that coal is mineral; it is dug out of deep mines.""Yes," said Norah, "so are clay, and stone, and sand, and iron, and rock-salt.
"But," said Fred, "these things We always in theground. Coal was not always in the ground. Teacher has been telling us fine stories of a time when the coal-beds were great forests of trees.""Yes," Willie joined in, "and he showed us somepieces of coal, with the shape leaves and ferns on them.""The forests some time or other sank down and got buried, and now they are changed into coal," added Fred.
"How strange!" said his sister, "And is it all true?" "Yes, teacher says it is quite true.""Would you like to see something very funny?" Fred went on.
"That I should," said his sister.
" T h e n w a t c h m e , " hesaid.
He brought out, in a very sly way, one of his father"s clay pipes, with a l o n g s te m . He h a d filled the bowl with small dusty coal, and closed it up with clay, just as he had seen teacher do.
He put the bowl of the pipe into the middle of the bright red fire.
"Now, little girl," said he, "just watch."In a little while they saw some puffs of yellow smoke come out at the end of the stem. The bowl too got red-hot. Then the pipe left off smoking.
"Now, Norah," said Fred, "watch again."
He put a light to the end of the pipe. A bright yellow flame burst out in a moment, and Norah gave quite a start.
"Whatever is that? "she said.
"Ah," said her brother, "we knew we should give you a surprise.
"That is gas burning at the mouth of the pipe- the very gas that burns in our streets, and shops, and houses."Norah had another surprise when the pipe was taken out of the fire. After it had got cool, Fred broke the bowl, and showed her that it was full of coke.
SUMMARY
Coal was not always in the ground, as it is now. It has been formed from the remains of great forests, which once grew on the earth. The trees, long, long ago, sank down and got buried and changed into coal.
Coal gives us gas to light our streets, and shops, and houses; and coke to burn in our fires.
Lesson 34
