Twice I got up early and ran along the banks of the Arno and, not for the first time, wished Brussels could have had a river worth the name. Cities with rivers have extra dimensions (for a start they have two banks) and inevitably lead to pleasing architectural configurations, including bridges, of course. I had the privilege of living and studying in Florence but I always learn something I didn’t know each time I return. This time it was a river-related fact that I happened across whilst paging through a book of old photographs in the Istituto degli Innocenti. The renaioli were sand diggers. They plied the Arno in special flat-bottomed boats, sounding the bottom with long poles to find sand banks. The sand would then be dug up and graded and was particularly used for restoration work. You can read about them here. Some boats still exist but the trade is now gone and thus so has the aspect of the river they once used to ply on a daily basis.