Editing Change ringing (section)

==Peals and quarter peals==
{{main|Peal}}
[[File:St Martins Birmingham peal board Queen Victoria Law Courts 1887.jpg| thumb|upright=1.2|A [[peal board]] at [[St Martin in the Bull Ring]], Birmingham, recording the details of a notable peal. Thousands of these boards exist in change-ringing belfries.]]

For some people, the ultimate goal of this system is to ring ''all'' the permutations, to ring a tower's bells in every possible order without repeating – what is called an ''extent'' (or sometimes, formerly, a ''full peal''). The feasibility of this depends on how many bells are involved: if a tower has ''n'' bells, they have ''n''! (read [[factorial]]) possible permutations, a number that becomes quite large as ''n'' grows.

For example, while six bells have 720 permutations, eight bells have 40,320; furthermore, 10! = 3,628,800, and 12! = 479,001,600. Estimating two seconds for each change (a reasonable pace), one finds that while an extent on six bells can be accomplished in half an hour, an extent on eight bells should take nearly twenty-two and a half hours. (When in 1963 ringers in [[Loughborough]] became the only band in history to achieve this feat on tower bells, it took them just under 18 hours.<ref>[http://www.cccbr.org.uk/rc/long_lengths/40320_plain_bob_major.html Online peal board], from the Central Council records committee {{webarchive |url=https://web.archive.org/web/20080613195450/http://www.cccbr.org.uk/rc/long_lengths/40320_plain_bob_major.html |date=June 13, 2008 }}</ref>) An extent on 12 bells would take over thirty years.

Since extents are obviously not always practicable, ringers more often undertake shorter performances. Such ringing starts and ends with rounds, having meanwhile visited only a subset of the available permutations; but ''truth'' is still considered essential — no row can ever be repeated; to do so would make the ringing ''false''. A ''[[peal]]'' is an extended performance; it must comprise at least 5000 changes (but 5040 on 7 bells). A performance of 1250 changes likewise makes a ''quarter peal'' (''quarter'' for short); a peal or a quarter tends to last about three hours or 45 minutes, respectively.<ref>{{cite web | url=https://framework.cccbr.org.uk/version2/fundamentals.html#touches | title=Framework for Method Ringing - Fundamentals of Method Ringing }}</ref>