Image of School Bell Image of School Bell

A nice little old sign with 'School Bell' on it,metal backing with silver and gold reflective foil and black paint,covered with beveled glass.
Maybe before modern technology there were so many bells for different things they needed a sign for each?
This one was bought in America from and antique dealer.
Approximately 95mm high x 130mm long,not large but very sweet and it has two holes on the sides to hang up.