There are two procedures for ringing changes. The first, and most simple, is for one of the ringers, the conductor, to ‘call’ a pair of bells to change places in the order of a change. The second, more difficult and complex, involves ringing a new change with each pull of the ropes. The ringers have to memorise patterns of changes known as ‘methods’, which prescribe when each pair of bells will change places. The bells begin in rounds and return to rounds without repeating any row along the way. The simplest method is called ‘plain hunt’ and is illustrated here using four bells.
The maximum number of different changes that can be rung on five bells is 120, on six bells it is 720, on seven it is 5040, on eight it is 40,320, and on twelve it is 479,001,600! At normal ringing speed it would take about 36 years non-stop to ring all the possible changes on twelve bells without repetition. It takes about three hours to ring 5040 changes. Since that is a moderate challenge, 5040 is chosen as the defining number of changes for a ‘peal’.