The Age of Reason by Thomas Paine: “I know, however, but of one ancient book that authoritatively challenges universal consent and belief, and that is Euclid's Elements of Geometry; [Euclid, according to chronological history, lived three hundred years before Christ, and about one hundred before Archimedes; he was of the city of Alexandria, in Egypt.”
The Pillars of the Earth by Ken Follett: “"I've been reading Euclid." Euclid's Elements of Geometry had been one of the first books translated.”
Cosmos by Alexander von Humboldt: “So he found a copy of Euclid's Elements of Geometry, and began to read.”