[Bell Historians] bell shapes

[Carl S Zimmerman]

At 20:09 +0000 2003/12/05, David Bryant wrote:
> > For these reasons, bellfounders who produce tuned change-ringing
>> bells, as the two surviving English founders and Eijsbouts do, must
>> have in hand a much wider range of profiles than those who only
>> produce single bells, small peals, or chimes and carillons.
>
>I think it's important to stress the point (which I'm sure Carl is aware
>of), that the trebles of a ring, although heavier than a bell of the same
>note cast as part of a chime or further round in a lighter ring, can still
>be of the same basic external profile as any bell of its diameter by that
>founder - it will be phyically bigger than a bell of the same note intended
>for another purpose, but will be thicker than a 'standard' bell of its
>diameter would be in order to make the note sharper. Of course, as I've
>already mentioned, there are higher-number rings where the trebles have
>long-waisted profiles, probably both for mechanical and weight reasons
>(Redcliffe is an example which springs to mind).
>
>Of course, thick trebles often need extra-heavy clappers to bring out their
>tone. The York Minster trebles have clapper balls of a similar diameter to
>the 10th!

Yes, I agree with "same basic external profile", at least in terms of 
the general visual appearance. But I don't think that a bellfounder 
can accomplish that simply by varying the distance between a standard 
pair of inner and outer sweeps. The peculiar shape of a bell, with 
its deliberately varying thickness from top to shoulder to waist to 
soundbow to lip, implies that one can't make it thicker or thinner 
overall by the simple methods that would work for pieces of timber or 
RSJ, because the thin parts would change much more (proportionately 
speaking) than the thick parts. So the founder who wants to make 
bells of varying weights for the same pitch must have several sets of 
sweeps to accomplish that, I think. Of course I am far from being an 
expert on this subject, having no direct practical knowledge of it at 
all, so I would very much like to read or hear a discourse about it 
from a foundryman who has actually done such work.

Carl