Four years ago I posted this photo of a strange phenomenon affecting our double-glazing. A strange spreading circle with a raggedy edge on the inside of the glass in the insulating cavity.
We were at a loss as to what they were or what they meant. Some sort of alien suburban crop circle, except on glass? A mutant algae that thrives in a vacuum? A mysterious message from the Planet Zog?
It took us a while, but we finally solved the mystery after other circles began to appear. They are caused by the suckers that the workmen used to carry the glass. Or so we’re led to believe.