"Swallow," Milton nodded.
"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 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 thunk it?"
"A gink," said Rhodes, "going into compressed air had better think it, or do it without thinking it. He may have his eardrums 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 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."