Last sun bath before winter?

OK, maybe the summer is not totally gone yet... At lunch time a lot of people go to the closest garden, take a chair and sit in the sun as long as they can. Talking about chairs, I remember when I was a little boy, you had to pay for these chairs. There was a sort of "Chair Police" - namely a garden keeper - who would come and go all day long and ask for money (it was probably very affordable) to the people already seated. I kept asking my mother: "How do they know who just sat and who already paid?!" I don't remember what her answer was...