Piston spacing

[DHM]

A couple of quick questions for the experts:
Is there a standard, or recommended, spacing distance between thumb pistons?
And should divisional pistons be placed centrally (i.e. should pistons 1 and 8 be equidistant from the left and right-hand ends of the keyboard)?
If you wanted extra thumb pistons for "Appel Anches" ventils (Ped, GO, Pos, Rec), where would you put them?

Thanks in advance for advice.

 

[Vox Humana]

I am sure the organ builders will have lots to say, but might a humble player offer his opinion? It's hard to beat the comfort of the large H&H consoles of the mid-1960s. That comfort included the piston spacings. It's difficult to find photos of these consoles taken square-on, but I found one of Coventry Cathedral. Here divisional 1 on each manual is placed under Middle C and #8 below the E a tenth higher, but so that the left-hand edge of the piston is flush with the left-hand edge of the key. The H&H I used to play daily as an organ scholar was constructed very similarly and seemed ideal. If you have more than 8 divisionals the extra ones will have to go to the right, but the further up the keyboard the pistons go the more inconvenient they are to reach while playing.  I suppose I would want "anches" pistons to be to the right of the divisionals, but I'd prefer to have them as foot pistons. After all, on French organs they are operated by the feet. However, if you have a lot of foot pistons, convenient placing could be a problem.

[Vox Humana]

I might add that the divisional pistons on my toaster begin under the B below Middle C and that is still perfectly comfortable for right-hand operation. No.8 falls only marginally to the right of the equivalent ones at Coventry, but it's enough to make it frequently more difficult to operate without taking the hand off the keys.

[pcnd5584]

I would agree with Vox. The piston spacings for most of Harrisons' consoles from this era are both ergonomically pleasing and visually elegant. Two exceptions are the consoles at Westminster Abbey and Winchester Cathedral (although these fall outside of the time-scale), which have larger spacings between the divisional pistons, and are neither as convenient nor as visually pleasant.

Westminster Abbey:

 

Winchester Cathedral: