Two leading researchers into ancient wisdom demonstrate that the earth's dimensions were accurately known prior to 3000 BC. These astonishing findings, available for the first time, include a system of surveying and measure based on simple numerical and geometrical rules documents that remnants of this science still existed in medieval times when it became lost. It appears that the system was applied world-wide. Chapters include: Measurement and the Moon; Stonehenge & the Lunation Triangle; The Preseli Triangle; Prehistoric Precision: A Summary; The Numbers that Measure the Earth; Traditions of Ancient Surveyors in Britain; Secrets of the 52nd Parallel; Dates and Speculations "A Summary; Appendices.