Sentence:  The more superficial beholder of the book's cover (a magnificent piece of artistry by the Venetian painter Gabriel Bella) will have failed to notice, on its continuation overleaf, the employee of an ancient <WSD>"jeu de paume</WSD>" who, having scaled the slanting roof of the gallery, is busily retrieving from the dusty recesses of the window-sill the stray tennis balls from below. 
Meaning of the word marked with <WSD> tags:  The type of court where this game was played.