Back in July we rented a cottage in St Mawes, Cornwall. It was a fattening week of cream teas, Cornish pasties and boat rides (sadly no sea swimming, the weather seems to have it in for us all this summer). On a rainy day we visited the maritime museum and discovered this Fresnal lens which was used to concentrate the light source in lighthouse lamps. Science aside, I was struck by how beautiful this functional object was. I love the symmetry, when you walk around it you see different layers of the glass and their reflections, quite extraordinary for something that was developed in the early 1800s.