1280px-Tremont_and_Boylston_Streets_by_ACGoodwinPicture: Entrances to the Boston subway line, Tremont and Boylston Streets, Boston (1915). Painting by Arthur C. Goodwin.

“Lynch & I were the last to go. His toothache excited my sympathy, but sympathy could not cure it. He left the [tram] car at the Boylston Street subway station, & thereafter I was alone.” — Lovecraft on attending the Hub Club Conference on 5th September 1920, Boston, at which he met Morton for the first time.

“Then we split up into narrow columns, each of which seemed drawn in a different direction. One disappeared in a narrow alley to the left, leaving only the echo of a shocking moan. Another filed down a weed-choked subway entrance, howling with a laughter that was mad.” — H.P. Lovecraft, “Nyarlathotep” (1920).

“God, how that man could paint! There was a study called ‘Subway Accident,’ in which a flock of the vile things were clambering up from some unknown catacomb through a crack in the floor of the Boston Street subway and attacking a crowd of people on the platform.” — H.P. Lovecraft, “Pickman’s Model” (1926).