For a while i've had a lingering interest in bell ringing
, but I've never really looked into it. I decided to node what I don't know
, and this is what I came up with.
A lot of bell ringing is for the purpose of celebrating the glory of god and other religious rituals, but not being the most theistic guy in the world, I find the mathematical and mechanical aspects far more interesting.
Mechanically, the bells are rung by rotating them in the vertical plane. The bell is attached to a rope in such a way that when the rope is pulled, the bell is inverted (with the open part of the bell at the top). When the rope is released, it swings down (pivoting around the top of the bell). Momentum causes it to continue swinging through almost 360 degrees, until the bell becomes inverted again.
A device called a stay (a.k.a block of wood) performs the dual tasks of stoping the bell from spinning indefintely, preventing the bellringer from being dragged into the bell tower and simultaneously dampening the hopes of Funniest Home Videos contestants everywhere.
With some assistance from the bellringer (pulling on the rope), the bell swings back though the arc again and returns to it's original position.
This kind of bell ringing motion is called full circle. One of the benefits of this motion is that during each swing of the bell, it is reasonably easy to predict the point at which the bell will ring (which is somewhere around the 300 degree mark).
While predictable, the bell generally rings about one second after each pull of the rope, which makes it quite challenging to ring the bell at an exact time.
Timimg becomes quite an issue, because in general, bells are rung in groups. Each bell in a group is tuned to a different note (normally adjacent notes in the C scale).
The order in which the different bells are rung is called a method. A method is made up of a sequence of changes. Each change is an arrangement causing each bell to be rung exactly once. The simplest method is called the plain hunt and it looks like this (each change is on a separate line).
The 1s show the tenor bell, which is the lowest pitched bell. In diagrams like the one above, it's place is traditionally highlighted (normally with a red line) and used as a reference point.
Notice that in the plain hunt, the position of each bell only moves by at most one position to the left (earlier) or to the right (later) in each change. This is due to the difficulty present in contolling the timing of the ring. One place adjustments can be made my slightly increasing or decreasing the speed of the swing of the bell. This places interesting restrictions on the different methods possible.
Methods come in varying lengths. For any given number of bells, there is a maximum number of unique changes. A method which contains all such changes is called a peal. Most peals are extremely long, for example, a 7 bell peal contains 5040 changes (7 factorial) and can take about 3 hours to ring. I'd guess this is a feat only attempted by l33t r1ng3rz :)
(a large quantity of this information was obtained from http://www.anzab.org.au and http://www.cb1.com/~john/ringing/ringing.html)