our sun? How many miles?"

"Miles?" questioned Gor. "We know the word, for the Mountain has told
us, but the length of a mile we could not know. This I can say: there
were wise men in the past when our own world was larger. They worked
magic with little marks on paper. It is said that they knew that if
one came here from our sun and kept on as far again through the solid
rock, he would reach the outside--the land, of the true sun, from
which our forefathers came."

Rawson nodded his head, while his eyes followed that sweeping green
bowl of the sea. "Not far off," he said abstractedly. "Two thousand
miles radius--and the earth itself not a solid ball, but a big
globular shell two thousand miles thick. I could rig up a level, I
suppose; work out an approximation of the curvature."

From the smooth winding path which they had followed there sounded
behind them hurrying footsteps; a moment later Loah stood beside him.

* * * * *

Her eyes gave unmistakable corroboration of what Gor had said of that
torrent of tears, but she looked at Dean bravely, while every show of
emotion was erased from her face. "You sent for me," she said.

And Rawson, though now he knew he could speak to her and be
understood, found himself at a loss for words.

"We wanted you with us, Gor and I," he began, then paused. She was so
different from the girl whose smiling eyes had welcomed him. The
change had come when he spoke those first words on his arrival, and
now she was so coldly impersonal.

"I wanted to thank you. You saved my life; you were so brave, so...."
Again he hesitated; he wanted to tell her how dear, how utterly
lovely, she had seemed.

"It was nothing; it has pleased me to do it," she said quietly, then
walked on ahead while the others followed. But Rawson knew that that
slim body was tense with repressed emotion. He had not realized how he
had looked forward to seeing again that welcoming light in her eyes.
He was still puzzling over the change as they entered a natural cave
in the mountainside.

A winding passage showed between sheer walls of snow white, where
giant crystals had parted along their planes of cleavage. Then the
passage grew dark, but he could see that ahead of them it opened to
form a wider space. There were lights on the walls of the room, lights
like the one that Loah had carried. And on the floor were rows of
tables where men were busy at work, writing endlessly on long sc