Douai Abbey bell

[Bill Hibbert]

Here is an excellent if extreme example of an usual effect in bell 
pitch.

I was eating my lunchtime sandwich in the car park at Douai Abbey 
(Woolhampton, Berkshire) the other day, as one does, and heard the 
Abbey bell chime several times for the lunchtime service. The bell 
sounded true harmonic with a major-third tierce. A check on the Abbey 
website showed that the bell is a French one, inscribed 'DROUOT 
FONDEUR A DOUAI NORD', and likely to date from the mid-late 19th 
century. At this point, I was getting excited: a 19th century true-
harmonic major tierce bell!

However, analysis of a recording taken the next lunchtime shows that 
the bell has the following figures:
Hum 428Hz -2494 cents
Prime 867Hz -1272 cents
Tierce 1064.5Hz -917 cents
Nominal 1808Hz.
(The tuning figures on the Abbey website, though right in proportion, 
are wrong absolutely, perhaps due to recorder speed). Based on these 
figures, the bells actually has both hum and prime broadly a semitone 
flat, and a flat minor tierce.

However, this bell is pitched not by the nominal but the prime, 
almost a semitone different (a predictable effect, by the new 
theories). As a result, the tierce sounds major, an effect enhanced 
by a major-third-ish higher partial.

I have read about Continental bells pitched by the prime but this is 
the first one I have personally investigated.

Bill H