Rung every morning, afternoon and at lunch time this device could be heard for miles.
Considered a welcome sound for class dismissal, it was hated by the more tardy pupils who were going to be late in the morning or returning from lunch break.
In the morning we would be marched into school, by class, to the strains of Martial music played through loudspeakers situated on the wall halfway up the staircases.
Remembered to this day, note-perfect, are The Dambusters March and the Royal Air Force March.