An organ's wind comes from an electric blower into a reservoir, and a gauge on the reservoir reads the pressure in inches of water, and with the blower off the reservoir sinks and the gauge falls to nothing in about a minute. This one holds three and a quarter inches with the blower off and the mains isolated, and at about the same hour on the days I am there, one pipe sounds.
I am an organ tuner, and this church is on my round twice a year.
How the wind works.
An electric blower fills a reservoir, which is a bellows weighted to hold a set pressure, and the pressure is read on a gauge, a U tube of water with a scale, in inches. When the blower is switched off the reservoir empties through the leaks that every organ has, and the gauge falls to zero in a minute or two, because there is nothing to hold it up.
You tune with the blower on. You leave with it off, and the gauge at nothing.
This organ's gauge holds three and a quarter inches with the blower off.
I first noticed it by accident: I came back from my lunch to an organ I had switched off and the gauge was where I had left it with the blower running.
I isolated the blower at the wall. The gauge held. I opened the reservoir's pallet, which lets the wind out, and heard it go, and closed it, and the gauge was at three and a quarter within a minute, from nothing, with no blower and no mains and no other way for wind to get in.
What has been checked.
The gauge. It is a tube of water. I have replaced the water. I have put a second gauge on the trunk.
The reservoir. Opened, inspected, releathered in 2022 because it was due. The new leather holds three and a quarter with the blower off.
The blower. Disconnected at the trunk, so that even a blower running by some fault could push nothing into the organ, and the gauge holds.
The building. A wind in the tower could in theory blow into a trunk with a leak in it, and I have sealed the trunk and tested on a still day, and the gauge holds.
The pipe.
Wind in a reservoir goes nowhere unless a pallet opens under a pipe, which is what a key does. With the keys untouched and the stops in, nothing should speak.
At about four in the afternoon, on the days I have been there, one pipe speaks. A single note, in the pedal, low, for about the length of a breath, and stops.
I have been at the console when it did it. No key moved. No stop was drawn. I have been in the organ chamber with my hand on the pallet of that pipe when it spoke, and the pallet opened under my fingers, the way it opens when a key is pressed, against the spring, and closed.
Which note.
I have written it down each time. It is the same note. It is the lowest note of a hymn tune that is in the book, and the tune is the one that was sung at the funeral of the organist who had the instrument for forty years, which I know because the present organist told me, when I asked, with no idea why I was asking.
What is done about it.
The organ is tuned, it is in good order, and the church is pleased with it. The wind pressure is right, which it is at all times, blower or no blower, which is not a fault a church would pay me to cure even if I knew how.
I have not told the organist about the pipe. She practises alone in the afternoons.
What I do.
I tune it.
The one thing I have changed is the time. I used to book that church for the afternoon because the light in the chamber is better after two.
I go in the morning now, and I am out by lunch, and the reason is the last afternoon visit, when the pipe spoke at four and I was in the chamber, with my hand on the pallet as it opened, and it opened wider than a key would open it, and what came was not one note but a chord, five pipes, the first chord of the tune, at three and a quarter inches of pressure, held for about a breath, with no blower and nobody at the console, and I took my hand off the pallet and went down the ladder and did not go back up.