e of the monorail with a guiding rail on
each side. The grooves for the rails with their three rollers are in
each car. There is a slight leakage of air here."

"You used the turbo type of blower, didn't you?"

"Had to because of the noise. We put some silencing devices on that and
yet we could not kill all of the racket. However a new invention has
come up that we will make use of soon now."

* * * * *

"But I can't understand, Dutch, why you seemed so put out when I
announced my intention of going to Europe via the Tube. Why, I can
remember the day when that would have tickled you to death."

"You followed the digging of the Tube, didn't you?"

"Yes, of course."

"You remember the volcano and lava seams?"

"Yes."

"Well, I do not believe that the crack was a pressure crevice. If it had
been, we were far enough below the ocean floor to have partly relieved
the situation by the unusually solid building of the Tube. The
tremendous shell of this new type of specially hardened metal--"

"And the rich concrete that was used as filling! That was one job no one
slipped up on. I remember how you watched it--"

"Yet the crack has widened, Bob, since the Tube was completed."

"How can you be certain?"

"By the amount of water coming through the drain pipes."

"But you said that once more it was stationary."

"Yes, and that is the very thing that proves, I believe, the nature of
the crack."

"I don't follow you."

"Why it isn't a crack at all, Bob. It is an earthquake fault."

"Good heavens, you don't mean--"

"Yes, I do. I mean that the next time the land slips our little tube
will be twisted up like a piece of string, or crushed like an eggshell.
That always was a rocky bit of land. I thought in going that far north,
though, that we had missed the main line of activity; I mean the
disturbances that had once wiped out a whole nation, if your scientists
are correct."

"Then you mean that it is only a matter of time?"

"Yes, and I have been informed by one expert that the old volcanic
activity is not dead either."

"So that is what has stolen away your laugh?"

"Well I am one of the engineers--and they won't suspend the service."

"Fate has played an ugly trick on you, Dutch, and through your own
dreams too. However, you have made me decide to go by the Tube."

He took his pipe out of his mouth and stared at me.

"Sooner or later the Tube will be through, and I have n