Pumping the organ

We're in St Philibert in Tournus. The main picture is of an upper chapel or room of enormous size and starkness - look at the staircase; how would you like to climb that?! The railings at the end are round the bellows for pumping air to the grand organ in the church, which is the other side of the wall at the far end. They require three people to pump them - there was no sign of any help from electricity. Top right is a detail of them. Bottom right is the grand organ itself, cradled on the West wall of the church.