THE CRYSTAL SUN. Rediscovering a lost technology of the ancient world Robert Temple. Arrow (Random House), London, 2000. Paperback, 642 pages, £7.99. ISBN 0-09-925679-7. Introduction by Sir Arthur C. Clarke.

This important book not only reveals Robert Temple’s startling discovery of over 450 optically ground lenses lying unrecognised in museums around the world but also proves, by practical example, the existence of a mass inability of scholars and scientists to break away from their existing theories when confronted by objects which simply do not fit in. They prefer to ignore them, file them away as `religious artifacts’. Temple ridicules this wilful ignorance as `Consensus Blindness’: he tells of museum curators refusing to accept the `objects’ as lenses even when their magnifying or reducing properties are demonstrated in front of them.
    Unlike many `alternative history’ books which have flooded the market over the last three years, Temple’s book is solidly based upon verifiable data and available objects: he found over 100 lenses from medieval Scandinavia, others from pre-Roman Britain, from the Roman Empire, from Troy (48 lenses), Ephesus (over 30 lenses), Carthage (16 lenses), Cyprus, Rhodes, and the Mesopotamian cultures which, in the 7th century BC, produced an eye-glass ground to correct for a specific type of astigmatism. The oldest lenses date from Egypt, perhaps 2500 BC, but the technology is much earlier: an ivory knife handle from around 3300 BC has microscopic carvings which could only have been executed by means of a magnifying lens. These ancient lenses were used not only for magnifying details but for monocles, spectacles and even telescopes: Strabo writes of seeing the Sun or Moon `through tubes’. Furthermore, the ancients used lenses, or small water-filled globes, to concentrate the sun’s rays in order to cauterise wounds or light fires, thus literally `bringing fire from heaven’.
    The discovery of all these lenses would seem enough but Temple is not one to stop half-way. He investigates the implications of this technology on the civilisations of the past: in lighthouses, the use of mirrors as reflective telescopes to see ships from great distances, and ancient surveying techniques by means of theodolites.
    This book is for those who want their investigation into mysteries of the past based upon fact, not speculative fiction. It is endlessly fascinating and thought provoking.
    Michael Baigent