Bass oboe. Nominal pitch: C basso.

Technical description: African blackwood with silver-plated keys. The sockets and reed-well are metal lined and the tenons are tipped with metal. Semi-automatic octave keys. Only the R2 plate directly covers a hole, the others close holes by means of axles. The L1 pierced plate mechanism is controlled by the L3 finger; L1 closes the hole completely, with L1 raised and L3 down the pierced plate is open. The holes closed by the R2 and R3 plates are position on the side of the instrument, next to the hole for the F key. The F key rises under a spring and (mysteriously) would be closed by the R3 plate. There is no forked-F vent but the mechanism opens the E♭ key when forked-F is fingered. The L4 lowB and E♭-dup keys are mounted on the upper section and has a double link to the lower section when the instrument is assembled so that both keys will operate. The lowC key closes the brille mechanism. The linkage between lowB and lowC has been disconnected. L0: TP; 81; 83. L1: PL; 82. L2: PL. L3: PL: D♭ tr. L4: G♯; lowB; E♭-dup. R0: sup. R1: PL. R2: PL. R3: PL; F. R4: lowC; C♯; E♭. Keymount type: pillars. Keyhead type: cups. Repair History: The thumbplate appears to have been added and the original conservatoire action has been removed although some parts of the original mechanism are still in place. A side hole has been plugged with cork and the associated key removed on the level of the G♯ key, this vent is present on the modern cor anglais. There are signs that the octave keys have been moved and the mechanism altered; the second octave key does not match the first in design and there are two filled holes at the top of the instrument. There is also a section of axle with no sleeve covering: this could be in connection with raising the usable pitch of the instrument at some point during its history. The 83 key may be a later addition as the key does not match the 81 key next to it. The link between lowB and C has been bent to disconnect it. The fact that the F key can be closed by the R3 plate suggests there have been other changes to the mechanism in this part of the instrument.