make up the number of changes in a peal. For larger numbers of bells a peal is a subset of the extent. The extent on eight bells comprises 40,320 changes, and would be referred to today as a long-length peal. Despite this, it has been successfully rung as a continuous performance both on tower and on hand bells, 17 hours in duration on tower bells. Relationship of extents and peals Modern peal standards Method ringing peals today consist of a minimum length of between 5000 and 5280 changes, or permutations, depending on the method, and the number of bells. The first method ringing peal in this modern sense took place at St Peter Mancroft Church in Norwich, in 1715, and was in the method "Grandsire Bob Triples", which is equivalent to the modern Plain Bob Triples. This is the earliest known record of a "full peal" which was "true" – that is, did not have any repeated changes – and was over 5,000 changes. There is a long list of rules which been developed since 1890. To be classified as a peal, a performance must be in accordances with rules and decisions of the Central Council of Church Bell Ringers, allowing them to be recorded in that organisation’s peal records. They must also be published in The Ringing World. The Central Council has two committees which are arbiters of the standards that peals must achieve: Methods committee Peal records committee Some key conditions required for all peals are: A peal shall start and end with rounds (bells sounding in numerical, ascending order), and shall be rung without interval. No row shall be struck more than once before the next change is made. Every bell must sound at every row throughout the peal. Each bell must be rung continuously by the same person or persons. For handbells the bells shall be retained in hand. For tower bells the bells shall be audible outside the building in which they are contained. No assistance of any kind shall be given to any ringer by any person not ringing in the peal. The use of physical aids to memory in conducting and ringing is not permitted. No error in calling shall be corrected later than during the change at which the call or change of method or non-method block would properly take effect. Any shift or error in ringing shall be corrected immediately. Challenges