human
About a man's ears, said he;
gpt
Crack?
human
Well, that's what we call it, but I don't suppose anything really cracks. After you get down, say, thirty feet, your ears hurt a good deal, especially if by chance you have a little cold; and you keep opening your mouth and swallering to make the crack come, and the first thing you know, you hear a sound inside your head like striking a match; that's the crack, and then you can go on down as far as you please, and you won't feel any more pain in your ears until you're coming up again; then you get a reverse crack. They say it's the air working in and out of your head. I don't know what it is, but I know some men's ears won't crack, and those men can't never make divers.
gpt
How deep can a diver go down?
human
I'll tell you about that some other day, said he.
gpt
It's pretty near time now for me to be sweeping up this coal.
human
he explained how they lessen the weight of a sunken barge by first pumping out the water in her, and then pumping out the coal. The same suction-pipe does both, and will discharge thirty-five or forty tons of coal an hour, on a chute which holds the coal while the water streams through. During this operation the diver is down in the barge, moving the suction-end back and forth, up and down--the
gpt
We pump grain out of wrecks in the same way, said Atkinson,
human
What!--with a hole in his suit?
gpt
That doesn't matter, as long as it's only in the leg. You see, the air in the helmet presses down hard enough to keep the water below a man's neck. But he mustn't bend over so as to let his helmet get lower than the hole.
human
I should say not!
gpt
Why, what would happen if he did?
human
He'd be killed quicker than you can wink. The air from the helmet would rush out at the hole, and he'd be crushed by the weight of the water.