It was a recurring theme throughout most of Golden Age fiction.
E.g. Clifford D. Simak mentions them as a mode of transportation in The Goblin Reservation, Asimov has them in Robots of Dawn, and I'm sure I'm forgetting plenty more.
It could be that it was Heinlein who kicked of the trend.
E.g. Clifford D. Simak mentions them as a mode of transportation in The Goblin Reservation, Asimov has them in Robots of Dawn, and I'm sure I'm forgetting plenty more.
It could be that it was Heinlein who kicked of the trend.