Nathaniel Gordon's "The Golden Judge" (short story, non-genre, humor, free): Ultimate "machine" to resolve international boundary disputes!
Caution: Readers from many places in the world will need to bear in mind the story had been written for US audiences.
Fact sheet.First published: Astounding, December 1955.
Download full text from Project Gutenberg, Manybooks, Feedbooks.
Download 43 minute audio read by Hollis Hanover at LibriVox.
Among the stories edited by John Campbell for Astounding/Analog.