[r-t] Candover Differential Place Doubles

[Philip Earis]

I've just seen Peter Hinton's interesting message from 3 July:

> This just caught my eye, as, although it's a Differential, all the
> working bells in fact follow the same blue line, but with offsets that
> aren't all multiples of 10. Is this unique?  It is interesting?

Candover Doubles has notation &5.1.5.123.5,1 = 15432

The property Peter highlights isn't unique - its reverse Lampton
Differential Place (&345.1.5.1.5,1 = 15432) has a RW reference of 55/811
on methods.org.uk, so I presume this was rung in 1955?  I'd be interested
to see if there was any article/discussion in the RW or CC squabble
archive about this, as it seems to be the oldest reference in the
"Differential Hunter" (yuk) list of methods on methods.org.uk.

The other closely-related rung doubles methods with the same property seem
to be:

Avington Differential Place Doubles
&5.145.5.1.5,1 = 14523

Old Alresford Differential Place Doubles
&5.1.125.1.5,1 = 14523

There are also differential doubles methods where the treble plain hunts
that have neat similar-but-different properties,  including where the two
groups of working bells ring palindromic reverses of each other:

Forton Differential Place Doubles
&345.145.5.1.5,1 = 14523

Herriard Differential Place Doubles
&5.1.125.123.5,1 = 15432

...and also an example where the two groups of working bells ring glide
reverses of each other:

Wallingford Differential Place Doubles
&345.1.5.123.345,123 = 13254

Of course, along these lines and even more elegant is the supreme
principle Banana Doubles (3.125.3.125.3.145.3.145 = 41253), about which
I've written a lot before.