Further to John Page's comments about pneumatic action church organs
and the speed of sound I would like to point out that such organs,
where the console is not close to the organ, can be difficult to play
by the uninitiated.

Robbie's comment that the speed of sound of 1.13 fpms being in the
hoses and in the sound in the air may reduce the effect is actually the
reverse of reality since the two delays are additive.  It only takes
a separation of 44 feet for the player to experience a 0.1 second delay
to the music, between his fingers operating the key and him hearing
that note.  On fast passages this is a very significant delay which can
have a disastrous effect on an inexperienced player.

Organ players must learn to ignore their ears when playing such organs.
This is easier said than done.

Regards, Nicholas Simons, UK