Zubdat al-tawarikh 16: Curious apartment.

16

One of the curiosities exhibited this year was manufactured by the most celebrated physician of the time, Hakím ’Alí. It filled every beholder with wonderment, however wise he might be. He built a room of about the ordinary breadth and length, to which the only entrance was at the top, by a sort of trap-door. Over the roof of the room he constructed a reservoir, which remained full of water, and no one could enter the room except by plunging into the bath. Upon reaching this single entrance, he gained access to the room, which he found furnished with carpets, books, and all the conveniences of a sitting room,—yet no water by any chance ever got into it. It is said that the King one day with some of his private companions got into the room in the way above indicated, and after remaining there some time enjoying their conversation, left it again by the passage through that single trap-door.