Vapour trails over Holborn

A beautiful, sunny day in London. I took myself off for a walk to Tottenham Court Road at lunchtime, salivated over soft furnishing and crockery in Habitat (though left unscathed), mourned over the empty shelves gathering dust in Fopp, and looked up to see countless vapour trails with planes overhead creating more. I wonder where the trails go - when I see a plane overhead, I think of all the excited people going on holiday to new places, or leaving London to go home or start new lives in a shiny, different place.