The Boy With the U. S. Life-Savers Part 11

"You remember that Father was interested in mines?"

"Of course," Eric answered; "he showed me that little model of a colliery he kept in his study."

"You do remember that," the other said, his eyes kindling. "I helped him make it. It was a lot of fun. Dad was a crank on conservation. He was one of the first men in America to take it up. You know it was his influence that swung Washington into line? The waste in coal really used to worry him. He was always afraid of a coal famine, and he spent a lot of time doping out ways to stop the waste in mining. He was just daffy about it, then."

"I can remember that, too," the boy said reminiscently. "He had pictures showing how quickly the coal was being used up, and how much coal every person in the United States was consuming, and all that sort of stuff.

It was always mighty interesting to me. Your dad and I got along finely together."

"You did," his friend agreed. "Well, after a while, Dad decided to drop his business in 'Frisco and go mining. He'd always kept close tabs on the coal question, so that, when he got ready to start, nothing would satisfy him but small holdings in half a dozen parts of the country."

"What for?"

"You see, Dad wasn't trying to make a pile of money out of mining; he wanted to experiment with all sorts of coal and find some way to use it so that there wouldn't be so much waste. The locomotive, for instance, only converts about thirty per cent. of the coal into power. The other seventy per cent. goes up the smokestack. Same thing with an ocean liner."

"I know," said the boy.

"All right. So Dad bought a mine in Illinois, and one in Manitoba, and took a half-share in some Minnesota mines and another in a Michigan mine. Then he joined a company in Pennsylvania, and I don't know what all. Anyhow, he's got stuff all over the place. It was out of the question for the rest of us to be traveling from mine to mine all the time, the way Dad jumps around, and so we settled here. It's sort of central for him.

"Being mixed up in such a lot of mines, Dad had a chance to work out some of his pet schemes. He'd always been enthusiastic over the government's relations with the miners, and when it started rescue work, he was one of the first to equip a rescue car and ask some of the experts to come out and instruct his miners how to handle it. You know Dad--everything he does, every one else has got to do?"

"He always was like that," Eric agreed.

"He's that way still. So, of course, I was elected to that first-aid business right away. I had to know it all! There's nothing half-way about Dad. Caesar's Ghost! How I slaved over that stuff! Luckily for me, they sent out a cracker-jack from Washington, and it was such good sport working with him that I soon picked it up. The next move was that I should go from one to another of Dad's mines and organize the rescue work. I've been doing that for the last year."

"I should think that was bully!" exclaimed Eric. "But how do you do it?"

"It's easy enough to start." The young fellow laughed. "I'm a regular rescue 'fan' now. I usually get two or three teams together and have a match. Talk about your kids on a baseball diamond in a vacant lot! Those miners' rescue teams have the youngsters skinned a mile for excitement when there's a rival test."

"But I don't see how you could have a fire-rescue match," said Eric, puzzled, "you can't set a mine on fire just to have a drill!"

"Scarcely! At least, you can't set a whole mine on fire. Once in a while, though, you can use an old mine shaft. But we generally do it in the field. There the entries and rooms are outlined with ropes on stakes. Across the entrances of these supposed rooms crossbars are laid, just the height of a mine gallery.

"The contest is to find out how good the men are, individually, and to teach them team work. Each man has a breathing apparatus, and a safety and electric lamp, while each crew has a canary bird."

"A what?"

"A canary bird!"

"What kind of a machine is that?" asked Eric, thinking the other was referring to some name for a piece of rescue apparatus.

"A canary bird? It's a yellow machine with feathers, and sings," said Ed, laughing.

"You mean a real canary bird?"

"Yes, a live one."

"But what the crickets do they need a canary bird for?"

"To give them a pointer as to when the air is bad. You see, Eric, there's all sorts of different kinds of poisonous gases in coal mines.

Some you can spot right off, but there's others you can't."

"I thought gas was just gas," Eric answered, "'damp,' don't they call it?"

"There's several different 'damps.' Take 'fire damp' or just plain 'gas'

as the miners call it. That's really methane, marsh gas, the same stuff that makes the will-o'-the-wisp you can see dancing around over a marsh.

It'll explode, all right, but there's got to be a lot of it around before much damage'll be done. 'Fire damp' is like a rattlesnake, he's a gentleman."

"How do you mean?" queried the boy.

"Well, just the same way that a rattler'll never strike before giving you warning, 'fire damp' always gives you a chance ahead of time."

"How?"

"You know every miner carries a safety lamp?"

"Yes."

"'Fire damp' makes a sort of little cap over the flame of the lamp, like a small sugar-loaf hat. As soon as a miner sees this, he knows that there's enough 'gas' around to make it dangerous. As it's a gas that it doesn't do much harm to breathe, you see he can always make a get-away.

Isn't that being a gentleman, all right?"

"Yes, I guess it is."

"Then there's 'black damp.' That's ordinary carbon dioxide, or carbonic acid gas."

"Isn't that just the stuff we breathe out?" questioned Eric.

"Exactly," his former schoolmate replied. "In an old mine, though, you've got to remember, nearly all the oxygen is absorbed by the coal.

That gives a lot less chance for a leak of carbonic acid gas to mix with enough oxygen to keep the air pure. For 'black damp' though, the lamp's a good guide again. When a miner sees that his lamp is beginning to burn dim, it's a sign the air's short of oxygen."

"Of course," said Eric, "we used to have that experiment in our high school chemistry."

"We did. But do you remember just how much oxygen a lamp has to have?"

"No," the boy was forced to admit, "I've plumb forgot."

"A safety lamp will go right out with less than seventeen per cent. of oxygen, while a man can live fairly comfortably on fifteen or sixteen per cent. So the flickering out of a lamp is a sure sign that the danger line's not far off."

"It's a gentleman, too, then," said Eric with a laugh.

"Yes," the other a.s.sented dubiously, "but there's less margin. Now, 'white damp,' or carbon monoxide, is a horse of a different color.

That's the real danger, Eric. Pretty nearly all the cases of poisoning in mines are due to 'white damp.' Just the other day, in Pennsylvania, two hundred men were killed--whouf!--just like blowing out a match. But 'white damp' hasn't got any effect on the flame of a safety lamp. If anything, it may hit it up even a trifle brighter. So the lamp isn't any good. That's where the mice come in."

"Mice? I thought you said canaries!"

"We use both mice and canaries. When you haven't got a canary, take a mouse."

"Which is the better?"

"Canary! 'White damp' catches him quicker. That means he gives an earlier warning. A canary will fall off his perch in four minutes when the air's only got one-fifth of one per cent, of 'white damp.'"