This bell has a very dull sound. Over damped they call it.
This is a Faith Bell, or Yi Bell, from China.
I have wanted one of these for 20 years! Now I finally got one.
I am very pleased.
The bell comes with a supporting frame and a wooden hammer
At the bottom of the frame is this little heater device
You put something in here, and set light to it, to heat up the bell.
So there will some science involved here.
Something happens when it warms up.
This infra red thermometer will tell us the starting temperature of the bell.
The two spots have to converge, to tell the temperature.
It is 31 degrees centigrade.
That is the ambient temperature of the room.
So now we heat the bell up to see what happens.
It is easier if I use this long candle.
Here we go...
It is methylated spirits
A very easy flame to keep under control.
Now we will see what happens as the temperature rises.
That now says 55 degrees
The sound is still as 'dull as ditch water'.
Over damped they call it.
It is now 64 degrees.
No sound at the top either.
Still no ringing sound at the bottom.
73 degrees. The temperature is shooting up!
Look at that - 80 degrees.
No, it is still sounding dull.
It is hardly a bell is it? Ah, 90 degrees.
Any sound yet?
That is definitely to sound a little more ...
... not quite resonant
That is definitely sounding more bell-like
And the temperature is 98, not quite 100 degrees
Aaah.... that is a bell sound
That is a proper resonant bell sound, and it is 105 degrees
So that is what this bell does. At ambient temperature, it sounds like dull wood...
when you reach 100 degrees, or just a bit more
that is a proper 'come to dinner bell' isn't it?
Wow!
What happens then when the bell cools down?
Well for that we have to turn off the flame, so we will put the lid on,
And now we can see what happens as the bell cools down.
It is still about 100 degrees
That is a nice sound, that is what a bell should sound like
Some of these bells apparently have different notes depending on how you hit it
It is coming down... 98 degrees
That is still quite a nice sound
It is now 94 degrees
It seems to heat up faster than it cools down
I think it has gone down by a quarter of a tone
Now it does not ring for such a long time
It is starting to get a little bit damped
It has dropped another quarter of a tone
It is now about 88 degrees
Starting to sound quite dull, much less resonance
Starting to sound quite wooden
At 100 degrees, the sound is superb.
And now it is getting duller and duller
All the way down to ambient temperature
which is about 30 degrees in this room
So at the critical temperature, about 100 degrees, it becomes a live bell
Extraordinary. What an amazing thing this is.
The Yi Bell, or Faith Bell.
Ask not for whom the bell tolls...
... it tolls for thee!