The Open Diapason: Preliminary Scales and Examples
The Open Diapason is the most complete of the extant ranks of this organ, with 29 pipes present. One of only 3 ranks to have what appear to be their original rackboards, each of the two for the Open Diapason have 22 holes, allowing for a total of 44 pipes. The organ's manual compass is 49 notes. Viewed from its underside, the Open Diapason toeboard has the same number of holes, as do the two sliders together. The difference of 5 pipe holes is accounted for as follows. There are two pipe toe holes at the right end of the toeboard that correspond to notches in the right upper support rail mounted halfway up the height of the pipe chamber; this appears to be part of the original configuration. However, changes were made at the left end of the toeboard. A total of 3 holes on the toeboard - the first one in the first row, the first two in the second - have been covered with wood and the rackboards altered to match. It is unknown when or why these changes took place; equally uncertain is whether Joseph Downer or a later organ serviceman was responsible.
Like the other 4 incomplete ranks, the pipes of the Open Diapason are presently in various states of completeness; see the photographs below for examples. In the Parts section of the Pipe Scales table, the following abbreviations represent the presence and/or attachment of the component parts of the pipes:
| A :: attatched | L :: loose | M :: missing | U :: unknown |
| M/L :: missing on 1st inspection, now matched, fitted & loosely attached | |||
| L/4 :: 4 sides present, but loosely attached in 2 to 4 connected sections | |||
| UB :: top unevenly beveled, may not be original voicing/construction | |||
| SB :: top bevel is "saddle" shaped on one or more sides, may not be original | |||
| Open Diapason: Examples: Condition & Completeness | |||||||||
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| original top bevel [f1] | saddle top [G#] | cut top [G] | complete pipe [B] - body, cap & foot | loose cap [D] - exposed block, inner side of cap | loose foot [e1] | loose sides [d1] | |||
Pipe scales and measurements were taken by James Stark, and were transcribed and annotated by Philip Maye, referring to the pipe detail photographs. The absence of measurements for certain parts of extant pipes may not necessarily indicate that those parts were either absent or inaccessible. Further measurement and study is needed.
Coming Soon: click on a pitch in the Note column to view an individual gallery for that pipe, including attached and separate parts, and original (pitch) and later markings.
| Open Diapason: Pipe Scales | ||||||||||||||||
| [mm] | ||||||||||||||||
| Pitch | Dimensions | Condition | Parts | |||||||||||||
| Note | Marked | Foot | Length | Width | Depth | Block Height | Cutup | Average Wall | Nominal Length | Halving | Complete Pipe | Original Top Bevel | Foot | Cap | Sides | Comments |
| [GG] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| [GG#] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| [AA] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| [AA#] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| [BB] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| [C] | --- | --- | --- | --- | --- | --- | --- | --- | 2' | --- | --- | --- | --- | --- | --- | --- |
| [C#] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| D | back | 98.4 | 508.0 | 41.3 | 42.9 | 26.99 | 6.4 | 6.3 | --- | --- | --- | UB | M/L | M/L | A | uneven bevel |
| [D#] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| E | back | 101.6 | 447.7 | 34.9 | 41.3 | --- | 6.4 | 4.8 | --- | --- | --- | UB | M/L | A | A | uneven bevel |
| [F] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| F# | back | --- | 396.9 | 31.8 | 38.1 | 25.40 | 6.4 | 5.0 | --- | --- | --- | SB | M | M/L | A | "saddle" bevel |
| G | front | 95.3 | 349.3 | 31.8 | 39.7 | 25.40 | 6.4 | 5.3 | --- | 18 | --- | --- | M/L | M/L | A | --- |
| G# | --- | 92.1 | 355.6 | 28.6 | 31.8 | 25.40 | 6.4 | 4.9 | --- | --- | --- | SB | M/L | M/L | A | "saddle" bevel |
| A | front | 92.1 | 304.8 | 28.6 | 31.8 | --- | 4.8 | 5.0 | --- | 18 | x | --- | A | A | A | --- |
| A# | back | 92.1 | 314.3 | 25.4 | 28.6 | 23.81 | 6.4 | 6.0 | --- | --- | --- | --- | M/L | A | A | B flat |
| B | front (bk) | 92.1 | 266.7 | 25.4 | 30.2 | --- | 4.8 | 4.7 | --- | --- | x | --- | A | A | A | --- |
| c1 | back | 92.1 | 266.7 | 25.4 | 27.0 | --- | 5.6 | 4.3 | 1' | 19 | --- | UB | M/L | A | uneven bevel | |
| c1# | front | 85.7 | 263.5 | 22.2 | 25.4 | --- | 4.8 | 4.5 | --- | --- | x | SB | A | A | A | "saddle" bevel |
| 426 Hz | ||||||||||||||||
| d1 | back | --- | 238.1 | 20.6 | 25.4 | 23.81 | 4.0 | 4.5 | --- | 17 | --- | UB | M | M/L | A | uneven bevel |
| d1# | front | --- | 228.6 | 19.1 | 22.2 | 19.05 | 4.0 | 4.0 | --- | --- | --- | x | M | M/L | L/4 | --- |
| e1 | back | 92.1 | 212.7 | 20.6 | 23.8 | --- | 3.2 | 4.3 | --- | --- | --- | x | M/L | A | A | --- |
| f1 | front | 92.1 | 200.0 | 22.2 | 23.8 | 17.46 | 4.8 | 4.1 | --- | --- | --- | x | A | M/L | A | --- |
| f1# | back | 95.3 | 193.7 | 15.9 | 20.6 | --- | 3.2 | 4.5 | --- | --- | x | x | A | A | A | --- |
| g1 | front (bk) | 95.3 | 190.05 | 14.3 | 19.1 | 15.88 | 4.8 | 4.3 | --- | --- | --- | --- | M/L | M/L | A | --- |
| g1# | --- | 92.1 | 158.8 | 15.9 | 15.9 | --- | 3.2 | 4.5 | --- | --- | --- | --- | M/L | A | A | --- |
| a1 | back | 92.1 | 144.5 | 17.5 | 17.5 | 19.05 | 3.2 | 3.7 | --- | --- | --- | --- | M/L | M/L | A | --- |
| [a1#] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | |
| b1 | front | 95.3 | 139.7 | 15.9 | 17.5 | --- | 3.2 | 3.7 | --- | --- | x | x | A | A | A | --- |
| c2 | back (fr) | 95.3 | 131.8 | 14.3 | 17.5 | --- | 3.2 | 3.8 | 1/2' | 19 | x | --- | A | A | A | 435 Hz |
| c2# | front | --- | 128.6 | 15.9 | 14.3 | 19.5 | 3.2 | 3.3 | --- | --- | --- | x | M | M | A | --- |
| d2 | back | 95.3 | 120.7 | 14.3 | 15.9 | --- | 4.8 | 3.2 | --- | 17 | --- | UB | A | M/L | A | uneven bevel |
| d2# | front | --- | 111.1 | 14.3 | 14.3 | --- | 3.2 | 2.9 | --- | --- | --- | --- | M | M | A | --- |
| e2 | back | --- | 98.4 | 14.3 | 15.9 | --- | --- | 3.1 | --- | --- | --- | --- | M | M/L | L/4 | 3 sections |
| f2 | front | --- | 81.3 | 12.7 | 11.1 | 12.7 | 3.2 | 2.8 | --- | --- | --- | x | M | M | A | --- |
| f2# | --- | --- | 92.1 | 11.1 | 12.7 | --- | 3.2 | 3.0 | --- | --- | --- | --- | M | M | A | even/no bevel |
| [g2] | -- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| g2# | back | --- | 76.2 | 11.1 | 11.1 | --- | 3.2 | 2.8 | --- | --- | --- | x | M | A | L/4 | 2 sections |
| [a2] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| a2# | back | 65.1 | 9.5 | 11.1 | 11.1 | missing | 3.2 | 2.9 | --- | --- | --- | U | M | M | U | block missing |
| [b2] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| [c3] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| [c3#] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| d3 | front | 82.6 | 44.5 | 6.4 | 7.9 | --- | 2.4 | 2.8 | --- | --- | x | UB | A | A | A | uneven bevel |
| [d3#] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| [e3] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| [f3] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| [f3#] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| [g3] | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |