"It's nothing to be scared of," he reassured her. "They say that the doors of Hall in Town used to open this way until someone broke a glass button on the wall. Come on."
There was another pair of glass doors that opened the same way as they approached. They led to a large reception room with a desk and chair opposite the door, chairs in a row along the wall. The floor was red tile, with a white line, about six inches wide, circling around to a door to the left.
Behind the desk was another door.
"Sightseers," said a voice from out of nowhere that made Theta scream, "will follow the white line through the door to the left. Those with business in the offices will consult the receptionist. Please proceed."
Almost in a state of trance, Henry led the way along the white line. The door opened and admitted them, then a second door.
Here everything was spotless, dustless, though no one had been there for years.
"You are now in the generating room," the voice began again. "The humidity is zero. All dirt and dust has been removed. What you bring in with you will be gone in five minutes."
They were on a balcony, looking down into a large space. On the floor below them seemed to be a huge cylinder, suspended between two metal-covered blocks. Only by the glimmering reflections from its polished surface could one tell that it was revolving.
"Before you is the main generator," the voice began again. "If you look closely you will note that the armature shaft does not touch its supporting bearings. It is held in suspension by polarized barumal obtained from Mars, so there is no friction and no wear. It is powered by water reduced to hydrogen and oxygen. The excess gases are used in the hoppers and storage bins to force out the air and preserve the foods on their way to their destinations. Some gas is piped to the disposal plants, in which all organic matter is converted into fertilizer."