Pluto
3 of the 6 encyclopedias on this shelf carry an entry for Pluto. All 3 are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
in classical mythology, the god of the lower world. An earlier Greek title was Hades, the Unseen, still preserved as the name of his dwelling place. By the Romans he was called usually Tartarus, Orcus, or Dis. Pluto means bestower of riches. It was given to this god as the patron of the mines. He was the brother of Zeus. His wife was Persephone, the daughter of Demeter. The Greek conception of the ruler of the dead was very different from the Christian conception of the devil. It was his duty simply to keep order in the lower world. He was in no way the subduer and seducer of mankind. He was stern and pitiless in the maintenance of discipline, but he was in no sense the enemy of the human race. As in the case of the devil, however, his appropriate color was black. Black cattle were sacrificed in his honor. See Demeter ; Hades
1000 Classical Characters (1900)
Known to the Greeks as Hades . Son of Saturn and Ops, who inherited his father's kingdom with his brothers, Jupiter and Neptune. He received as his portion the kingdom of the infernal regions, of death, and funerals. He seized Proserpine as she was gathering flowers, and, carrying her away on his chariot, she became his wife and queen of the infernal regions.
Collier's New Encyclopedia (1921)
in mythology, the son of port second only safe anchorage Saturn and Ops, inherited his father's secure a stupendous breakwater has been con- . kingdom with his brothers, Jupiter and structed at a cost of about $10,000,000 Neptune. He received as his share the infernal regions. All the goddesses refused to marry him; but, on seeing Proserpine, the daughter of Ceres, gathering flowers in the plains of Enna, in Sicily, , and immehe became enamored of her diately carried her away. Black victims, and particularly a bull, were the only sacrifices offered to him. The dog Cerberus watched at his feet, the harpies hovered around him, Proserpine sat on his left, and the Parcæ occupied his by some the right hand. Pluto is called father of the Eumenides.
What Has Changed in the Last Century
The mythology in these entries still stands: Pluto (Greek Hades), brother of Zeus and Poseidon, ruler of the dead, husband of the abducted Persephone, honoured with black victims. What none of these writers could know is that the name was about to be attached to something new — Clyde Tombaugh found a body beyond Neptune at Lowell Observatory in 1930, and it was christened Pluto on the suggestion of an eleven-year-old English girl, Venetia Burney, so that today most readers meet the word as an astronomical rather than a mythological term. That Pluto was reclassified as a "dwarf planet" by the International Astronomical Union in 2006 and was photographed close up by the New Horizons spacecraft in July 2015. On the god himself the main scholarly refinement is a tidier separation of names: Tartarus, which Aiton's lists as a Roman title, is now generally treated as a place in the underworld rather than a name for its ruler, the Latin equivalents being Dis Pater and Orcus.
Written for this edition, 2026.