Or would it be the stale air and incense out and rain and snow in?
A tricky question really because it would all depend on which faith the the church that had this ventilator fitted followed. Whichever devil dodging pursuit was the favourite in the church that this small architectural detailing came from the designer of the ventilator, and the architect who commissioned him right down to the foundry man who did the sand-casting of the ironwork deserve a pat on the back. A simple detail that has been made into a work of art in my eyes.
In reality it probably came from a catalogue and they simply said three of number 15a on page 23 in wrought iron please. Is the end of next week OK?
Even that approach doesn't spoil it, at least they could produce it. And they did it really well.
Every time I fill the bird bath I can enjoy the wrought ironwork, it's really heavy too. The wrought iron work not the birdbath.