Just past Leibniz’s house, Princess Caroline turned left towards the river, and so began a sort of voyage through time. This began on a quaint, curving Hanover street, which looked essentially medieval, and concluded, a quarter of an hour later, on the outskirts of the city’s fortification complex: a sculpture in rammed and carved earth as à la mode , and as carefully tended, as any lady’s hairstyle in the Grand Salon of Versailles. The Leine threaded its way through this in whatever way was most advantageous to the engineers. In some places it had been compressed into a chute, like meat funneled into a wurst-casing, and in others it was given leave to spread out and inundate ground that was considered vulnerable.