Back in the 1980s, when you rounded the corner on the top deck of a Number 36 bus at Vauxhall, you were rewarded by a glimpse into the milk bottle depot where tight queues of clean milk bottles wobbled on a conveyor, past the industrial-glazed windows on their way back into circulation. For some reason, this was a mysterious and oddly romantic sight. The lines of bottles seemed to be heading on a longer-than-necessary journey, backwards and forwards, through gleaming chrome machinery that was curiously complex. And they were clean: so sparkling clean! The glass positively twinkled under the fluorescent ceiling tubes, the contours of their lips etched out sharply in gleaming light. Oddly, you never saw a human being. It was as though the bottles had found their way there independently and lined up patiently, having made the decision themselves to be recycled. I think this was the most riveting thing of all.