Spreckels Organ Society
Insider Brunch and Tour

May 9, 2015

62-Brunch 09 May, 2015, at 12.12.31

When he plays the pedals, or presses down a large number of keys,
the pressure in the room drops. To compensate, this wall instantly pushes into the room,
effectively reducing the size of the room. This keeps the pressure constant.

Photo by Mike Cox