"Well!" he said. "Who taught you that?"
"Open the door."
The corridor beyond the door was lined—walls, ceiling and floor—with a silvery metal. It continued east a hundred yards or so, swung north and then went east again, widening all the time.
It ended in a great room whose far wall was glass or some equally transparent substance. The room was a huge observatory at the end of Superior but below its rim. They could look down from it, not without a touch of nausea, to the Earth four miles below.
Don, thinking of the surface of Superior above, thought it was as if they were looking out of the gondola slung beneath a dirigible.
Or from one of the lower portholes in a giant flying saucer.
V
There were clouds below that occasionally hid the Earth from sight. For a minute or more they gazed in silence at the magnificent view.
"This wasn't built in a day," Jen Jervis said at last.