"Great Barmecide, swallow what?"
"Swallow the pain, Bill. For look you. Deglutition opens the Eustachian tube. Some of the dense air enters the drum and counteracts the pressure on the outside of the membrane. You keep on swallowing. The air in the drum becomes as dense as that outside; there is no pressure on the membrane now—or, rather, the pressures are in perfect equilibrium—and, presto and abracadabra, the pain is gone."
"Who would have thought it?"
"A gink," said Rhodes, "going into compressed air had better think it. He may have his ear-drums burst in if he doesn't."
"But why does the Eustachian tube open only when we swallow?"
"To shut from the ear the sounds produced in the throat and the mouth. If the tube were always open, our heads would be so many bedlams."
"Wonderful nature!" I exclaimed.
"Oh, she does fairly well," admitted Milton Rhodes.
"And I suppose," I said, "that the pain in the ears experienced by those who ascend high mountains is to be explained in the same way, only vice versa. They, too, ought to swallow."
"Of course. At lofty heights, the dense air in the drum presses the membrane outward. Swallowing permits the dense air to escape. One swallows until the pressure on the inside equals that of the rarefied outside air, and, hocus-pocus and presto, the pain has evaporated."
"I hope," I said, "that all our difficulties will be as easily resolved."
"Hey!" cried Milton.
"What's the matter now?"
"Stop swallowing that water! We've got food sufficient for a week, but we haven't got water to last a week or anything like it. Keep up that guzzling, and your canteen will be empty before sunset."
"Sunset? Sweet Pluto! Sunrise, sunset or high noon, it's all the same here in Erebus."
"You'll say that it's very different," dryly remarked Milton Rhodes, "if you find the fingers of thirst at your throat."
"Surely there is water in this place—somewhere."
"Most certainly there is. But we don't know how far we are from that somewhere. And, until we get to it, our policy, Bill, must be one of watchful conservation."
A silence ensued. I sank into profound and gloomy meditation. Four thousand feet down. A mile deeper, and where should we be? The prospect certainly was, from any point of view, dark and mysterious enough to satisfy the wildest dreams of a Poe or a Doré. To imagine a Dante's Inferno, however, is one thing and to find yourself in it is quite another. 'Tis true, we were not in it yet; but we were on our way.
I hasten to say, though, that I had no thoughts of turning back. No such thought, even the slightest, was entertained for.one single moment. I did not blink, that was all. I believed our enterprize was a very dangerous one; I believed it was very probable that we should never return to the light of the sun. Such thoughts are not pleasant, are, indeed, horrible. And yet, in the very horror of them, I found a strange fascination. Yes, we might leave our bones in this underground world, in this very gallery even. Even so, we should have our own exceeding great reward. For ours would be the guerdon of dying in a stranger, a more wonderful quest, than any science or discovery ever had known. A strange reward, and perhaps you wonder what such a reward can mean to a dying or a dead man. All I have to say is that,
