This is a painting of a sound and the sound is not in it.
I want to be exact about the sound before I talk about the canvas. It is a single tone, brief, high, somewhere around three thousand hertz. It repeats about once a minute. It is loud enough to wake you and short enough that by the time you are awake it is over, and the frequency is chosen so that the human ear cannot localise it. A tone that short at that pitch gives your two ears almost nothing to compare. You will stand in the middle of your own hallway at four in the morning turning slowly, and you will be wrong about which room it is in, and you will be wrong again on the second chirp, and the third.
This is not a design failure. It is a chosen tone. The whole reason a smoke alarm is loud and hard to place is so that it cannot be slept through and cannot be ignored from a chair. And that property, which exists for the fire, gets reused without amendment for the low-battery signal.
So the device demands maintenance in the voice it was given for catastrophe. It has one alphabet. It says the only two things it knows in nearly the same way, and I am fairly sure it has never had occasion to say the other one.
Three forty is my own hour and I will not make more of that than it deserves. I was on a night route for eleven years and I know exactly what the city sounds like at that time, which is nothing, and then one thing.
Now the painting. There was no way to put the tone on the canvas and I tried three ways and threw all of them out. Rings coming off the housing, which looked like a diagram. A brightening of the diode at the moment of the chirp, which is a lie, because the flash and the chirp are not synchronised on this model. A wall of the room going pale, which was worse.
What I painted instead is the web.
It runs off the lower rim of the housing in a slack sheet, gathers into a single strand, and drops down and across the ceiling to the crown moulding, and it is the longest continuous line in the series. It picks up the red from the diode along its upper edge and it is otherwise nearly invisible. I painted it at the instant the sound was happening.
It is not moving. There is not enough energy in a two-hundred-millisecond tone to disturb a silk thread eighteen inches away, and there is nobody in the room to move the air either. The one physical object in range of the sound is unaffected by it.
I stood under that thing for a long time waiting for it to go again. When it did I looked at the web instead of the alarm, which is how I know.