They walked toward this.  Xenophilius greeted the guard by name and Luna politely curtsied.  He responded with a tip of his wizard’s hat and waved them through.  They traveled down a long, steep ramp heading down a wide hallway.  Along the walls were portraits of former great wizard and witch librarians.  Each whispered words of advice as Luna passed in front of them.  A waspish-looking crone whispered sharply, “Be quiet at all times!”  A severe old gentleman warned quietly, “Removal of items from the library is a punishable offense!”  A flamboyant middle-aged witch in multicolored garb smiled while saying, “Reading is Legilimental.”

When the ramp leveled off and they exited the passage, the Great Chamber of the British Library of Magic spread out before them.  The most striking thing about this room was the tremendous gap² in front of them.  The distance across was at least equal to the length of a city block.  This separated the entrance from the library levels.  Spanning it was a single, elegant, spare arc of white marble wide enough for a dragon to cross.  Curving in a mighty arch above her was another chandelier-hung, white marble ceiling.