Quite true. It is merely an assumption, and I will admit that Mr. Bennet's determination upon reigning in his wife's spending could be the sole reason that it seems quite clear that he never has given, and never will give, a ball.
In point of fact, the book refers to Elizabeth entering the "drawing room" at Netherfield, and the chapter in question makes no reference to a dedicated ball room.
In point of fact, the book refers to Elizabeth entering the "drawing room" at Netherfield, and the chapter in question makes no reference to a dedicated ball room.