A gas gun is a propane cylinder, a valve, a timer and a pipe, and it makes one bang per measured puff of gas. Mine fires between rounds with the valve shut, the timer off and the cylinder disconnected, and the cylinder on the shed scales is lighter every morning by the weight of the shots.
I grow cherries and the gas gun in the top orchard is the only thing standing between me and the starlings.
How a gas gun works.
A propane cylinder feeds a valve. A timer opens the valve for a moment, gas fills a chamber, a spark lights it, and it goes off like a shotgun. You set the interval, it runs from dawn to dusk in the season, and by law it is silent at night.
Each shot uses a set amount of gas, a few grams. I weigh the cylinder on the shed scales when I change it, and the drop in weight divided by the grams per shot is the number of shots, and it agrees with the timer's count to within a handful. That is not something I do out of interest. It is how I know I am not running a gun past its permitted rate.
The gun in the top orchard fires at night.
Not on the timer. The timer is set to stop at dusk and it does. Between about two and four in the morning it fires four or five times, at irregular gaps, and the neighbours hear it and so do I.
I turned the gas off at the cylinder valve. It fires.
I disconnected the cylinder and took it to the shed. It fires.
I took the gun out of the orchard and locked it in the shed beside the cylinder. Something in the top orchard fires, four or five times, between two and four, at the pitch and the length of a gas gun going off.
The cylinder.
That is the part I want an engineer to explain, because a bang in an empty field is a noise and a noise can be a great many things.
The cylinder in the shed, disconnected from anything, capped, on the scales, is lighter every morning after a night of it. Thirty eight grams on a night of five bangs, thirty on a night of four. About seven and a half grams a shot, which is what that gun uses.
I have weighed it on the shed scales, on the kitchen scales, and on the scales at the agricultural merchant's, and the merchant's man said the cylinder was losing gas and I should check the valve for a leak, and I said it was capped, and he checked it himself with soapy water and there was no leak.
What has been checked.
The gun. Serviced, then replaced with a new one, then removed altogether for a fortnight. The nights carried on.
The cylinder. Three different cylinders from two suppliers. Each one loses weight in the shed on the nights the orchard fires.
The neighbours. I have asked, because the honest answer would be that somebody has a gun of their own and I am hearing that. Nobody has one and the noise, they all say, comes from my top orchard.
The orchard at night. I have stood in it, at the gun's post, at two in the morning, four times. It has fired on two of them, from the post, from the empty bracket where the gun bolts on, with the gun in the shed, and the smell afterwards was propane.
What the starlings do.
They stay off. That is the one part of this that works in my favour and I would be lying if I said I had not noticed. The top orchard has the lowest bird damage on the farm, in the season and out of it, and the gun has not been in it since May.
What is done about it.
The council has had one complaint about a gas gun at night, in 2022, and the officer came out and found the gun in the shed with the timer off and wrote that no offence had been committed, and asked me, on the way to his car, what the noise was, and I said I did not know.
I have not put the gun back. It is in the shed. The cylinder is on the scales and I write the weight down every morning in the book I used to write the shot count in.
What I do.
I grow cherries and I keep the book.
The one change is that I moved the scales.
They were on the bench under the window, and the cylinder sat on them, and I read them first thing with my coffee.
They are in the middle of the floor now, with a chalk line round them, because in June I came in at half past six and the cylinder was on the scales where I had left it, thirty grams lighter, with the cap on, and the scales' feet had left four fresh marks on the bench three inches to the left of where the scales were standing, and the scales weigh eleven kilos and I had not moved them.