Perhaps it was because nobody until now has been willing to recognise that lenses existed in antiquity, and that the crystal sun idea was overlooked, and has never been described in any books on the history of science or philosophy. However, it appears in my latest book The Crystal Sun, the paperback of which is published by Arrow (London) in Britain and Australia on 1 February. The hardback, from Century (London), has been available in Australia since May, 2000.