Editing Change ringing (section)

==Technique and physics==
{{Main article|Ring of bells}}[[Image:bells.devon.750pix.jpg|thumb|upright=1.3|Bell ringing at St Mary and St Gabriel's Church, [[Stoke Gabriel]], [[Devon]], England. This is in the "ringing chamber".]]

[[File:St bees bells in down position.JPG|thumb|upright=1.3|The bells of [[St Bees Priory]] in [[Cumbria]] shown in the "down" position, where they are normally left between ringing sessions. This is in the "bell chamber".]]
[[File:St Bees bells in up position.jpg|thumb|upright=1.3|The bells of St Bees Priory shown in the "up" position. When being rung they swing through a full circle from mouth upwards round to mouth upwards, and then back again.]]
[[File:KirkbymooresiteBellRinging6bellsWebM.webm|thumb|upright=1.3|thumbtime=88|6 bells being rung to call changes in All Saints' Church, [[Kirkbymoorside]], in [[North Yorkshire]]]]
Today, some towers have as many as sixteen bells that can be rung together, though six or eight bells are more common. The highest pitch bell is known as the ''treble'', and the lowest is the ''tenor''. In some towers, a bell larger than a tenor that is present would be called a ''[[Bourdon (bell)|bourdon]]''. The bourdon is not part of the change ringing peal; it is hung from a pivoted beam. For convenience, the bells are referred to by number, with the treble being number 1 and the other bells numbered by their pitch&mdash;2, 3, 4, etc.&mdash;sequentially down the scale. (This system often seems counter-intuitive to musicians, who are used to a numbering that ascends with pitch.) The bells are usually tuned to a [[diatonic]] major [[Scale (music)|scale]], with the tenor bell being the tonic (or key) note of the scale. Some towers contain additional bells so that different subsets of the full number can be rung, still to a diatonic scale.<ref>{{cite web|last1=Bryant|first1=David|title=The History and Use of Semitone Bells|url=http://www.inspirewebdesign.com/ringsof12/tower_articles/a_semitones.htm|access-date=11 June 2014}}</ref> For instance, many 12-bell towers have a ''flat sixth'',<ref>This again may seem counter-intuitive to musicians. A ''flat sixth'' in a 12-bell ring is in fact the flattened 7th of the scale. A ''sharp second'' bell is a sharpened 11th (or 4th in the upper, incomplete octave) of the scale. For example, assume the bells are tuned to C-G'. A flat sixth is B{{music|flat}} allowing F-F' to be a scale. The sharp second is F'{{music|sharp}}, giving G-G' as the scale.</ref> which if rung instead of the normal number 6 bell allows 2 to 9 to be rung as light diatonic octave; other variations are also possible.<ref>[http://dove.cccbr.org.uk/detail.php?searchString=Worcester&numPerPage=10&Submit=++Go++&searchBells=12%2B&searchAmount=%3D&searchMetric=cwt&sortBy=Place&sortDir=Asc&DoveID=WORCESTER Dove entry for] [[Worcester Cathedral]], a twelve bell tower with 3 semi-tone bells. [http://dove.cccbr.org.uk/dove.php?searchString=&numPerPage=10&Submit=++Go++&searchCountry=&searchDiocese=&searchPracN=&searchRingable=&searchBells=13%2B&searchNote=&searchAmount=%3D&searchWeight=&searchMetric=cwt&searchDetails=&searchGF=&searchSimulator=&searchToilet=&sortBy=Place&sortDir=Asc Search on Dove's Guide for towers with 13 or more bells], note that [[Christ Church Cathedral, Dublin]] is listed as having 16 bells, with additional sharp 6, 9 and 13; [[Swan Bells]], [[Perth, Western Australia]], is again a 16 but with additional flat 3 and 10. Retrieved 28 May 2008.</ref> 
[[File:English full circle bell mechanism.png|thumb|upright=1.3|Mechanism of a bell hung for English full-circle ringing]]
The bells in a tower reside in the ''bell chamber'' or ''belfry'' usually with [[Louver|louvred windows]] to enable the sound to escape.

The bells are mounted within a ''bellframe'' of steel or wood. Each bell is suspended from a ''headstock'' fitted on trunnions (plain or non-friction bearings) mounted to the belfry framework so that the bell assembly can rotate. When stationary in the ''down'' position, the [[centre of mass]] of the bell and clapper is appreciably below the centreline of the trunnion supports, giving a [[pendulum|pendulous]] effect to the assembly, and this dynamic is controlled by the ringer's rope. The headstock is fitted with a wooden ''stay'', which, in conjunction with a ''slider'', limits maximum rotational movement to a little less than 370 degrees. To the headstock a large wooden wheel is fitted and to which a rope is attached. The rope wraps and unwraps on the rim of the wheel as the bell rotates backwards and forwards. This is [[full circle ringing]] and quite different from fixed or limited motion bells, which ''chime''. Within the bell the ''clapper'' is constrained to swing in the direction that the bell swings. The clapper is a rigid steel or wrought iron bar with a large ball to strike the bell. The thickest part of the mouth of bell is called the soundbow and it is against this that the ball strikes. Beyond the ball is a ''flight'', which controls the speed of the clapper. In very small bells this can be nearly as long as the rest of the clapper.

Below the bell chamber there may be one or more sound chambers, (one of which is likely to house the clock mechanism if the church has one) and through which the rope passes before it drops into the ''ringing chamber'' or room. Typically, the rope's length is such that it falls close to or on to the floor of the ringing chamber. About {{convert|5|ft|m}} from the floor, the rope has a woollen grip called the ''sally'' (usually around {{convert|4|ft|m}} long) while the lower end of the rope is doubled over to form an easily held ''tail-end''.

Unattended bells are normally left hanging in the normal ("down") position, but prior to being rung, the bells are ''rung up''. In the down position, the bells are safe if a person touches them or pulls a rope. A bell that is up is dangerous to be near, and only expert ringers should ever contemplate entering a bell chamber or touching a rope when the bells are up. To raise a bell, the ringer pulls on the rope and starts the bell swinging. Each time the bell swings the ringer adds a little more energy to the system, similar to pushing a child's swing. Eventually there is enough energy for the bell to swing right up and be left over-centre just beyond the balance point with the stay resting against the slider to hold the bell in position, ready to be rung.

Bellringers typically stand in a circle around the ringing chamber, each managing one rope. Bells and their attendant ropes are so mounted that the ropes are pulled in a circular sequence, usually clockwise, starting with the lightest (treble) bell and descending to the heaviest (tenor). To ring the bell, the ringer first pulls the sally towards the floor, upsetting the bell's balance and swinging it on its bearings. As the bell swings downwards the rope unwinds from the wheel and the ringer adds enough pull to counteract friction and air resistance. The bell winds the rope back onto the other side of the wheel as it rises and the ringer can slow (or ''check'') the rise of the bell if required.

The rope is attached to one side of the wheel so that a different amount of rope is wound on and off as it swings to and fro. The first stroke is the ''handstroke'' with a small amount of rope on the wheel. The ringer pulls on the sally and when the bell swings up it draws up more rope onto the wheel and the sally rises to, or beyond, the ceiling. The ringer keeps hold of the tail-end of the rope to control the bell. After a controlled pause with the bell, on or close to its balancing point, the ringer rings the ''backstroke'' by pulling the tail-end, causing the bell to swing back towards its starting position. As the sally rises, the ringer catches it to pause the bell at its balance position.

In English-style ringing the bell is rung up such that the clapper is resting on the lower edge of the bell when the bell is on the stay. During each swing, the clapper travels faster than the bell, eventually striking the soundbow and making the bell sound. The bell ''speaks'' roughly when horizontal as it rises, thus projecting the sound outwards. The clapper rebounds very slightly, allowing the bell to ring. At the balance point, the clapper passes over the top and rests against the soundbow.

In change ringing where the order the bells are struck in is constantly altered, it is necessary to time the swing so that this strike occurs with precise positioning within the overall pattern. Precision of striking is important at all times. To ring quickly, the bell must not complete the full 360 degrees before swinging back in the opposite direction; while ringing slowly, the ringer waits with the bell held at the balance, before allowing it to swing back. To achieve this, the ringer must work with the bell's momentum, applying just the right amount of effort during the pull that the bell swings as far as required and no further. This allows two adjacent bells to reverse positions, the quicker bell passing the slower bell to establish a new pattern. Although ringing up certainly involves some physical exertion, actual ringing should rely more on practised skill than mere brute force. Even the smallest bell in a tower is much heavier than the person ringing it.  The heaviest bell hung for full-circle ringing is in [[Liverpool Cathedral]] and weighs {{long ton||82|0|11}}.<ref>{{cite web|url=http://www.whitechapelbellfoundry.co.uk/foundry.htm |title=500 Years of History |publisher=Whitechapel Bell Foundry }}</ref><ref>{{cite web|url=http://dove.cccbr.org.uk/detail.php?searchString=Liverpool&Submit=+Go+&DoveID=LIVERPL|title=Liverpool:Cathedral Church of Christ|work=Dove's Guide for Church Bell Ringers|publisher=Central Council for Church Bell Ringers|access-date=2 May 2015}}</ref>  Despite this colossal weight, it can be safely rung by one (experienced) ringer.

(Whilst heavier bells exist – for example [[Clock Tower, Palace of Westminster|Big Ben]] – they are generally only chimed, either by swinging the bell slightly or having the bell hung dead and using a mechanical hammer.)