“The whole of this floor must have been transparent once,” said the Keeper of the Records. “When this chamber was sealed and the shaft built, the engineers must have done something to make the center opaque. Do you understand what it is, Alvin?”
“I think so,” replied the boy. “It’s a map of the transport system, and those little circles must be the other cities of Earth. I can just see names beside them, but they’re too faint to read.”
“There must have been some form of internal illumination once,” said Rorden absently. He was looking towards the walls of the chamber.
“I thought so!” he exclaimed. “Do you see how all these radiating lines lead towards the small tunnels?”
Alvin had noticed that besides the great arches of the moving ways there were innumerable smaller tunnels leading out of the chamber-tunnels that sloped downwards instead of up.
Rorden continued without waiting for a reply.
“It was a magnificent system. People would come down the moving ways, select the place they wished to visit, and then follow the appropriate Hue on the map.”
“And what happens then?” said Alvin.
As usual, Rorden refused to speculate.
“I haven’t enough information,” he answered. “I wish we could read the names of those cities!” he complained, changing the subject abruptly.