1. Navigation in Nature -- 2. The Early Navigators -- 3. Historical Background to Astronomy -- 4. Modern Astronomy -- 5. Navigation at Sea -- 6. The Longitude Problem -- 7. The Quartz Revolution -- 8. Classical Atomic Frequency Standards -- 9. Atomic and Molecular Oscillators -- 01. Field Confinement of Ions -- 11. Optical Frequency Oscillators: Lasers -- 21. The Gyrocompass -- 31. Radio Navigation -- 41. Satellite Navigation: GPS Space Segment -- 51. Satellite Navigation: GPS Control Segment -- 61. Satellite Navigation: GPS User Segment -- 71. Space Navigation -- 81. The Future of Navigation