Interest representation

The twenty-seventh entry is le plafond des dons, and the first noun has a piece of building work fossilised inside it. Le plafond is a ceiling, and it began as two words, plat fond, a flat bottom. That is the ceiling as the room below sees it: not the top of anything, but the underside of the floor above, and flat where a vault would not be. Modern French has carried the word into money and left the plaster behind. Le plafond de la dette is the debt ceiling, le plafond de verre the glass ceiling, and the verb built on it does two jobs: plafonner les dons is to cap them, while les ventes plafonnent says sales have stopped rising. The opposite limit is furnished from the same room, un prix plancher, a floor price, so that a French text sets its range between a floor and a flat bottom. English needs two words here: « a cap », a lid put on from above, and « a ceiling », the view from inside the room.