Two years ago I was in Paris for the New Year. The shops were gay with decorations, and polyhedra were obviously in fashion. I was particularly impressed with a lampshade which was a feature of many of the decorations; it was in the form of an icosidodecahedron, the pentagonal faces being dimpled, and with “petals” added, so that the whole resembled the flower of a Golden Chalice (Solandra grandifloral). Eventually I found a little shop by Notre Dame which would sell me one; I found myself the purchaser of a small box containing twenty strips of card, about 35 cm by 7 cm, which I was assured would make up into the lampshade I required.