Identify the modern day conveniences being referenced as "wagons which moved without horses," and "lights which burned without flame." Why do you think the names we use are no longer in use?

These words were cut long ago. There is green mould in the grooves of the letters and yellow streaks on the marble, which come from more years than men could count. And these words are the truth, for they are written on the Palace of the World Council, and the World Council is the body of all truth. Thus has it been ever since the Great Rebirth, and farther back than that no memory can reach.

But we must never speak of the times before the Great Rebirth, else we are sentenced to three years in the Palace of Corrective Detention. It is only the Old Ones who whisper about it in the evenings, in the Home of the Useless. They whisper many strange things, of the towers which rose to the sky, in those Unmentionable Times, and of the wagons which moved without horses, and of the lights which burned without flame.