Graham had been looking up as he came out upon the balcony, and the things he saw above and opposed to him had at first seized his attention to the exclusion of anything else.
Then suddenly he discovered the roadway! It was not a roadway at all, as Graham understood such things, for in the nineteenth century the only roads and streets were beaten tracks of motionless earth, jostling rivulets of vehicles between narrow footways.

But this roadway was three hundred feet across, and it moved; it moved, all save the middle, the lowest part.

For a moment, the motion dazzled his mind.

Then he understood.

Under the balcony this extraordinary roadway ran swiftly to Graham's right, an endless flow rushing along as fast as a nineteenth century express train, an endless platform of narrow transverse overlapping slats with little interspaces that permitted it to follow the curvatures of the street.