[O]ne of the great roof walkers of the world… talks about vertigo as a beast that has to be tamed piece by piece, that can never be overcome all at once.

Vertigo, he says, is not the fear that you will fall. It is the fear that you will jump. That, of course, is the thing that, when you are roof walking, you are taming. You are trying to unmoor your sense of danger and of not being able to trust yourself not to jump from your sense of beauty and the vision of a city that you get up high.

I roof-walk for very practical reasons: to see views that would otherwise be not really available to me in an increasingly privatized City of London.