The outline of this egg is an example of a Euclidean four point compass and straight edge egg construction. This particular construction was first published in 1954 by two Cambridge mathematicians, Cundy and Rollett, as a dissection puzzle to be cut out of card. Many more such constructions are to be found in Robert Dixon’s marvellous book Mathographics. The cross-section varies from a golden section rectangle at the bottom to a horizontal diamond at the top.