Just before Lord Milborne ("Uncle Francis") arrives, Lady Caroline is seen playing a pianoforte, but the sound heard during her playing is a harpsichord, not a pianoforte.
Asphalt is seen on the road in the scene when Lady Caroline arrives at Belgrave Village. Asphalt was not in use in England until several decades after this story takes place.
Just before Lord Milborne ("Uncle Francis") arrives, Lady Caroline is seen playing a pianoforte, but the sound heard during her playing is a harpsichord.