Primer Of Celestial Navigation

Primer of Celestial Navigation Primer of Celestial Navigation By John Favill, M. D. Associate Member, U, S. Naval Institute Navigator, U. S. Power Squadrons Colonel, Inactive Reserve, U. S. Army Third Edition Revised and Enlarged New York-1944 Cornell Maritime Press Acknowledgments For answering bothersome questions or for helpful sug gestions, the authors sincere thanks go to P, V. H. Weems, Lt. Comdr., U. S. Navy Ret., Professor Harlan T. Stetson of the Massachusetts Institute of Technology, Mr. Alfred F. Loomis, Secretary of Yachting, and Selwyn A. Anderson, Master Mariner. Contents Preface to Third Edition xiii Introduction xv Part I Fundamentals 1. Astronomical 3 2. Time 24 3. The Nautical Almanac 51 4. Altitudes 55 5. The Sextant 61 6. The Compass 69 7. The Astronomical Triangle 79 8. Trigonometry 82 9. Logarithms 92 Part II Procedures 10. Introduction to Position Finding 99 11. Latitude 103 12. Longitude and Chronometer Error 1 14 1 3 . Azimuth and Compass Error 117 14. Sumner Lines of Position 123 15. The Saint-Hilaire Method 128 16. Short-Cut Systems 134 17. Special Fixes 141 18. Polar Position Finding 148 19. Identification 155 20. Tabular Summary 157 Part HI Supplementary 21. The Sailings, Dead Reckoning, and Current 161 22. The Days Work 180 23. Essential Equipment 182 24. Practical Points 183 25. Navigators Stars and Planets 196 26. Reference Rules for Book Problems 205 27. Finding G. C. T. and Date 207 28. Abbreviations 209 29. Forms 212 30. Problems 224 Selected Bibliography 259 Index 261 List of Illustrations 1. Declination, 8 2. Excess of One Rotation 13 3. Diagram for General Orientation facing page 1 3 4. Phases of the Moon 18 5. Precession of the Equinoxes 20 6. TheEarths Orbit 23 7. The Solar Year 27 8. Time Diagram 33 9. Time Diagram 33 10. Time Diagram 33 11. Time Diagram 34 12. Time Diagram 34 13. Time Diagram 35 14. Time Diagram 35 15. Time Diagram 36 16. Time Diagram 36 17. Time Diagram 37 18. Relations Between Zone Time and Local Civil Time 40 19. Zone Time of Mean Sun Noons in Zone 40 20. Time Frame 44 21. The Opposite-the-Sun Meridian 45 22. Time Frame and O. S. M. 45 23. Change of Date 46 24. Refraction 57 25. Parallax 58 26. Sextant 61 ix 27. Sextant Angles 62 28. Arc and Vernier Scales 64 29. Reading the Sextant 66 30. Compass Card 71 3 1 . The Astronomical Triangle 79 32. For Napiers Rules 87 33. Angles in the Different Quadrants 89 34. The Four Cases of Latitude from Meridian Alti tude Observation 104 35. Latitude by Phi Prime, Phi Second 1 1 1 36. Longitude by Time Sight 1 14 37. Azimuth ng 38. Zenith Distance and the Radius of the Circle of Equal Altitude 125 39. The Saint-Hilaire Method 131 40. Rules for H. O. 211 136 41. Plane Sailing 163 42. Middle Latitude Sailing 166 43. First Current Problem 176 44. Second Current Problem 178 45. FixbyH. O. 214. D. R. Position 242 46. Fix by H. O. 2 1 4. Assumed Position 244 List of Tables 1. The Solar System 4 2. The Brightest Heavenly Bodies 7 3. Declinations of Navigational Stars 17 4. Time 30 5. Calculations of t 36 6. Zone Time 41 7. Compass Errors 74 8. Finding Deviation 75 9. For Magnetic Steer Compass 76 10. Compass Points and Quarter Points 78 1 1 . Finding Parts o the Astronomical Triangle 80 12. Definition of the Trigonometric Functions of Plane Right Triangles 83 13. Equivalents of the Trigonometric Functions of One Acute Angle of a Plane Right Tritegl when Hypotenuse 1 P 14.Trigonometric Functions o Any Angle with the Sign for Each Quadrant 86 15. Equivalent Trigonometric Functions of Angles in the Different Quadrants 88 16. Examples of Logarithms 96 17. For Correcting Polar Position Lines 152 18. Summary of Methods facing page 157 19. Rules for Time and Angles 206 20. For Finding G. C. T. and Date 208 21. Working Form for Azimuth by H. O. 214 233