📚 The Commonplace Books
Holmes's hand-indexed encyclopaedia of everything: biographies of vampires filed beside Victor Lynch the forger, "Vanderbilt and the Yeggman", voyages of the Gloria Scott. His external memory — the ancestor of every tool on this site.
The original brain attic
Holmes maintains a vast hand-indexed encyclopaedia of his own making — great scrapbooks in which he files everything a detective might one day need: potted biographies of villains, notable cases, cuttings from the agony columns, the voyages of ships. Under a single letter he can turn up a vampire legend, Victor Lynch the forger, and 'Vanderbilt and the Yeggman' on the same page.
The ancestor of every tool on this site
The commonplace books are Holmes's external memory — the physical counterpart to his mental 'brain attic', in which he refuses to store anything useless. They are, in spirit, the direct forebear of the reference tools, memory palaces and knowledge engines collected on Elementary Tools: a mind that knew a stocked archive beats raw brilliance, a century before the database.
Who it touches
Where it appears
The Adventure of the Sussex Vampire
1924
A mother caught sucking blood from her baby's neck; the vampire is a loving woman drawing poison, and the monster is a jealous boy with a South American bow.
The Adventure of the Empty House
1903
Holmes returns from the dead with a wax bust in the window and Colonel Moran's air-gun in the dark — the great hiatus ends with a snap of handcuffs.